diff options
Diffstat (limited to 'pkg')
42 files changed, 2898 insertions, 213 deletions
diff --git a/pkg/abi/linux/fuse.go b/pkg/abi/linux/fuse.go index d3ebbccc4..5c6ffe4a3 100644 --- a/pkg/abi/linux/fuse.go +++ b/pkg/abi/linux/fuse.go @@ -141,3 +141,108 @@ type FUSEWriteIn struct { _ uint32 } + +// FUSE_INIT flags, consistent with the ones in include/uapi/linux/fuse.h. +const ( + FUSE_ASYNC_READ = 1 << 0 + FUSE_POSIX_LOCKS = 1 << 1 + FUSE_FILE_OPS = 1 << 2 + FUSE_ATOMIC_O_TRUNC = 1 << 3 + FUSE_EXPORT_SUPPORT = 1 << 4 + FUSE_BIG_WRITES = 1 << 5 + FUSE_DONT_MASK = 1 << 6 + FUSE_SPLICE_WRITE = 1 << 7 + FUSE_SPLICE_MOVE = 1 << 8 + FUSE_SPLICE_READ = 1 << 9 + FUSE_FLOCK_LOCKS = 1 << 10 + FUSE_HAS_IOCTL_DIR = 1 << 11 + FUSE_AUTO_INVAL_DATA = 1 << 12 + FUSE_DO_READDIRPLUS = 1 << 13 + FUSE_READDIRPLUS_AUTO = 1 << 14 + FUSE_ASYNC_DIO = 1 << 15 + FUSE_WRITEBACK_CACHE = 1 << 16 + FUSE_NO_OPEN_SUPPORT = 1 << 17 + FUSE_PARALLEL_DIROPS = 1 << 18 + FUSE_HANDLE_KILLPRIV = 1 << 19 + FUSE_POSIX_ACL = 1 << 20 + FUSE_ABORT_ERROR = 1 << 21 + FUSE_MAX_PAGES = 1 << 22 + FUSE_CACHE_SYMLINKS = 1 << 23 + FUSE_NO_OPENDIR_SUPPORT = 1 << 24 + FUSE_EXPLICIT_INVAL_DATA = 1 << 25 + FUSE_MAP_ALIGNMENT = 1 << 26 +) + +// currently supported FUSE protocol version numbers. +const ( + FUSE_KERNEL_VERSION = 7 + FUSE_KERNEL_MINOR_VERSION = 31 +) + +// FUSEInitIn is the request sent by the kernel to the daemon, +// to negotiate the version and flags. +// +// +marshal +type FUSEInitIn struct { + // Major version supported by kernel. + Major uint32 + + // Minor version supported by the kernel. + Minor uint32 + + // MaxReadahead is the maximum number of bytes to read-ahead + // decided by the kernel. + MaxReadahead uint32 + + // Flags of this init request. + Flags uint32 +} + +// FUSEInitOut is the reply sent by the daemon to the kernel +// for FUSEInitIn. +// +// +marshal +type FUSEInitOut struct { + // Major version supported by daemon. + Major uint32 + + // Minor version supported by daemon. + Minor uint32 + + // MaxReadahead is the maximum number of bytes to read-ahead. + // Decided by the daemon, after receiving the value from kernel. + MaxReadahead uint32 + + // Flags of this init reply. + Flags uint32 + + // MaxBackground is the maximum number of pending background requests + // that the daemon wants. + MaxBackground uint16 + + // CongestionThreshold is the daemon-decided threshold for + // the number of the pending background requests. + CongestionThreshold uint16 + + // MaxWrite is the daemon's maximum size of a write buffer. + // Kernel adjusts it to the minimum (fuse/init.go:fuseMinMaxWrite). + // if the value from daemon is too small. + MaxWrite uint32 + + // TimeGran is the daemon's time granularity for mtime and ctime metadata. + // The unit is nanosecond. + // Value should be power of 10. + // 1 indicates full nanosecond granularity support. + TimeGran uint32 + + // MaxPages is the daemon's maximum number of pages for one write operation. + // Kernel adjusts it to the maximum (fuse/init.go:FUSE_MAX_MAX_PAGES). + // if the value from daemon is too large. + MaxPages uint16 + + // MapAlignment is an unknown field and not used by this package at this moment. + // Use as a placeholder to be consistent with the FUSE protocol. + MapAlignment uint16 + + _ [8]uint32 +} diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go index f36470e8d..7b02b74eb 100644 --- a/pkg/abi/linux/linux_abi_autogen_unsafe.go +++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go @@ -17,6 +17,8 @@ import ( var _ marshal.Marshallable = (*ControlMessageCredentials)(nil) var _ marshal.Marshallable = (*FUSEHeaderIn)(nil) var _ marshal.Marshallable = (*FUSEHeaderOut)(nil) +var _ marshal.Marshallable = (*FUSEInitIn)(nil) +var _ marshal.Marshallable = (*FUSEInitOut)(nil) var _ marshal.Marshallable = (*FUSEOpID)(nil) var _ marshal.Marshallable = (*FUSEOpcode)(nil) var _ marshal.Marshallable = (*FUSEWriteIn)(nil) @@ -32,6 +34,7 @@ var _ marshal.Marshallable = (*NumaPolicy)(nil) var _ marshal.Marshallable = (*RSeqCriticalSection)(nil) var _ marshal.Marshallable = (*RobustListHead)(nil) var _ marshal.Marshallable = (*SignalSet)(nil) +var _ marshal.Marshallable = (*SockAddrInet)(nil) var _ marshal.Marshallable = (*Statfs)(nil) var _ marshal.Marshallable = (*Statx)(nil) var _ marshal.Marshallable = (*StatxTimestamp)(nil) @@ -142,7 +145,7 @@ func (s *Statx) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (s *Statx) Packed() bool { - return s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() + return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. @@ -168,7 +171,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) { // CopyOutN implements marshal.Marshallable.CopyOutN. //go:nosplit func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { - if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() { + if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes. buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. s.MarshalBytes(buf) // escapes: fallback. @@ -198,7 +201,7 @@ func (s *Statx) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { // CopyIn implements marshal.Marshallable.CopyIn. //go:nosplit func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { - if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() { + if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to UnmarshalBytes. buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. length, err := task.CopyInBytes(addr, buf) // escapes: okay. @@ -224,7 +227,7 @@ func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { // WriteTo implements io.WriterTo.WriteTo. func (s *Statx) WriteTo(w io.Writer) (int64, error) { - if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { + if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes. buf := make([]byte, s.SizeBytes()) s.MarshalBytes(buf) @@ -617,7 +620,7 @@ func (f *FUSEHeaderIn) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (f *FUSEHeaderIn) Packed() bool { - return f.Opcode.Packed() && f.Unique.Packed() + return f.Unique.Packed() && f.Opcode.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. @@ -673,7 +676,7 @@ func (f *FUSEHeaderIn) CopyOut(task marshal.Task, addr usermem.Addr) (int, error // CopyIn implements marshal.Marshallable.CopyIn. //go:nosplit func (f *FUSEHeaderIn) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { - if !f.Unique.Packed() && f.Opcode.Packed() { + if !f.Opcode.Packed() && f.Unique.Packed() { // Type FUSEHeaderIn doesn't have a packed layout in memory, fall back to UnmarshalBytes. buf := task.CopyScratchBuffer(f.SizeBytes()) // escapes: okay. length, err := task.CopyInBytes(addr, buf) // escapes: okay. @@ -968,6 +971,237 @@ func (f *FUSEWriteIn) WriteTo(w io.Writer) (int64, error) { } // SizeBytes implements marshal.Marshallable.SizeBytes. +func (f *FUSEInitIn) SizeBytes() int { + return 16 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (f *FUSEInitIn) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Major)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Minor)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.MaxReadahead)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Flags)) + dst = dst[4:] +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (f *FUSEInitIn) UnmarshalBytes(src []byte) { + f.Major = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.Minor = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.MaxReadahead = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.Flags = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (f *FUSEInitIn) Packed() bool { + return true +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (f *FUSEInitIn) MarshalUnsafe(dst []byte) { + safecopy.CopyIn(dst, unsafe.Pointer(f)) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (f *FUSEInitIn) UnmarshalUnsafe(src []byte) { + safecopy.CopyOut(unsafe.Pointer(f), src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (f *FUSEInitIn) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (f *FUSEInitIn) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { + return f.CopyOutN(task, addr, f.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (f *FUSEInitIn) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := task.CopyInBytes(addr, buf) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (f *FUSEInitIn) WriteTo(w io.Writer) (int64, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := w.Write(buf) + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return int64(length), err +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (f *FUSEInitOut) SizeBytes() int { + return 32 + + 4*8 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (f *FUSEInitOut) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Major)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Minor)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.MaxReadahead)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.Flags)) + dst = dst[4:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(f.MaxBackground)) + dst = dst[2:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(f.CongestionThreshold)) + dst = dst[2:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.MaxWrite)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(f.TimeGran)) + dst = dst[4:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(f.MaxPages)) + dst = dst[2:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(f.MapAlignment)) + dst = dst[2:] + // Padding: dst[:sizeof(uint32)*8] ~= [8]uint32{0} + dst = dst[4*(8):] +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (f *FUSEInitOut) UnmarshalBytes(src []byte) { + f.Major = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.Minor = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.MaxReadahead = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.Flags = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.MaxBackground = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + f.CongestionThreshold = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + f.MaxWrite = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.TimeGran = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + f.MaxPages = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + f.MapAlignment = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + // Padding: ~ copy([8]uint32(f._), src[:sizeof(uint32)*8]) + src = src[4*(8):] +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (f *FUSEInitOut) Packed() bool { + return true +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (f *FUSEInitOut) MarshalUnsafe(dst []byte) { + safecopy.CopyIn(dst, unsafe.Pointer(f)) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (f *FUSEInitOut) UnmarshalUnsafe(src []byte) { + safecopy.CopyOut(unsafe.Pointer(f), src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (f *FUSEInitOut) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (f *FUSEInitOut) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { + return f.CopyOutN(task, addr, f.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (f *FUSEInitOut) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := task.CopyInBytes(addr, buf) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (f *FUSEInitOut) WriteTo(w io.Writer) (int64, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(f))) + hdr.Len = f.SizeBytes() + hdr.Cap = f.SizeBytes() + + length, err := w.Write(buf) + // Since we bypassed the compiler's escape analysis, indicate that f + // must live until the use above. + runtime.KeepAlive(f) + return int64(length), err +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. func (r *RobustListHead) SizeBytes() int { return 24 } @@ -1584,7 +1818,7 @@ func (i *IPTIP) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (i *IPTIP) Packed() bool { - return i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() + return i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. @@ -1599,7 +1833,7 @@ func (i *IPTIP) MarshalUnsafe(dst []byte) { // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. func (i *IPTIP) UnmarshalUnsafe(src []byte) { - if i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() { + if i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() { safecopy.CopyOut(unsafe.Pointer(i), src) } else { // Type IPTIP doesn't have a packed layout in memory, fallback to UnmarshalBytes. @@ -1666,7 +1900,7 @@ func (i *IPTIP) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { // WriteTo implements io.WriterTo.WriteTo. func (i *IPTIP) WriteTo(w io.Writer) (int64, error) { - if !i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() { + if !i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() { // Type IPTIP doesn't have a packed layout in memory, fall back to MarshalBytes. buf := make([]byte, i.SizeBytes()) i.MarshalBytes(buf) @@ -2455,6 +2689,144 @@ func (i *InetAddr) WriteTo(w io.Writer) (int64, error) { } // SizeBytes implements marshal.Marshallable.SizeBytes. +func (s *SockAddrInet) SizeBytes() int { + return 4 + + (*InetAddr)(nil).SizeBytes() + + 1*8 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (s *SockAddrInet) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint16(dst[:2], uint16(s.Family)) + dst = dst[2:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(s.Port)) + dst = dst[2:] + s.Addr.MarshalBytes(dst[:s.Addr.SizeBytes()]) + dst = dst[s.Addr.SizeBytes():] + // Padding: dst[:sizeof(uint8)*8] ~= [8]uint8{0} + dst = dst[1*(8):] +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (s *SockAddrInet) UnmarshalBytes(src []byte) { + s.Family = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + s.Port = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + s.Addr.UnmarshalBytes(src[:s.Addr.SizeBytes()]) + src = src[s.Addr.SizeBytes():] + // Padding: ~ copy([8]uint8(s._), src[:sizeof(uint8)*8]) + src = src[1*(8):] +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (s *SockAddrInet) Packed() bool { + return s.Addr.Packed() +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (s *SockAddrInet) MarshalUnsafe(dst []byte) { + if s.Addr.Packed() { + safecopy.CopyIn(dst, unsafe.Pointer(s)) + } else { + // Type SockAddrInet doesn't have a packed layout in memory, fallback to MarshalBytes. + s.MarshalBytes(dst) + } +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (s *SockAddrInet) UnmarshalUnsafe(src []byte) { + if s.Addr.Packed() { + safecopy.CopyOut(unsafe.Pointer(s), src) + } else { + // Type SockAddrInet doesn't have a packed layout in memory, fallback to UnmarshalBytes. + s.UnmarshalBytes(src) + } +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (s *SockAddrInet) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { + if !s.Addr.Packed() { + // Type SockAddrInet doesn't have a packed layout in memory, fall back to MarshalBytes. + buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. + s.MarshalBytes(buf) // escapes: fallback. + return task.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + } + + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (s *SockAddrInet) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { + return s.CopyOutN(task, addr, s.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (s *SockAddrInet) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { + if !s.Addr.Packed() { + // Type SockAddrInet doesn't have a packed layout in memory, fall back to UnmarshalBytes. + buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. + length, err := task.CopyInBytes(addr, buf) // escapes: okay. + // Unmarshal unconditionally. If we had a short copy-in, this results in a + // partially unmarshalled struct. + s.UnmarshalBytes(buf) // escapes: fallback. + return length, err + } + + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := task.CopyInBytes(addr, buf) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (s *SockAddrInet) WriteTo(w io.Writer) (int64, error) { + if !s.Addr.Packed() { + // Type SockAddrInet doesn't have a packed layout in memory, fall back to MarshalBytes. + buf := make([]byte, s.SizeBytes()) + s.MarshalBytes(buf) + length, err := w.Write(buf) + return int64(length), err + } + + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := w.Write(buf) + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) + return int64(length), err +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. func (l *Linger) SizeBytes() int { return 8 } diff --git a/pkg/abi/linux/netfilter.go b/pkg/abi/linux/netfilter.go index a91f9f018..9c27f7bb2 100644 --- a/pkg/abi/linux/netfilter.go +++ b/pkg/abi/linux/netfilter.go @@ -59,7 +59,7 @@ var VerdictStrings = map[int32]string{ NF_RETURN: "RETURN", } -// Socket options. These correspond to values in +// Socket options for SOL_SOCKET. These correspond to values in // include/uapi/linux/netfilter_ipv4/ip_tables.h. const ( IPT_BASE_CTL = 64 @@ -74,6 +74,12 @@ const ( IPT_SO_GET_MAX = IPT_SO_GET_REVISION_TARGET ) +// Socket option for SOL_IP. This corresponds to the value in +// include/uapi/linux/netfilter_ipv4.h. +const ( + SO_ORIGINAL_DST = 80 +) + // Name lengths. These correspond to values in // include/uapi/linux/netfilter/x_tables.h. const ( diff --git a/pkg/abi/linux/socket.go b/pkg/abi/linux/socket.go index c24a8216e..d6946bb82 100644 --- a/pkg/abi/linux/socket.go +++ b/pkg/abi/linux/socket.go @@ -239,11 +239,13 @@ const SockAddrMax = 128 type InetAddr [4]byte // SockAddrInet is struct sockaddr_in, from uapi/linux/in.h. +// +// +marshal type SockAddrInet struct { Family uint16 Port uint16 Addr InetAddr - Zero [8]uint8 // pad to sizeof(struct sockaddr). + _ [8]uint8 // pad to sizeof(struct sockaddr). } // InetMulticastRequest is struct ip_mreq, from uapi/linux/in.h. diff --git a/pkg/sentry/fdimport/fdimport.go b/pkg/sentry/fdimport/fdimport.go index a4199f9e9..b8686adb4 100644 --- a/pkg/sentry/fdimport/fdimport.go +++ b/pkg/sentry/fdimport/fdimport.go @@ -15,6 +15,8 @@ package fdimport import ( + "fmt" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/host" @@ -84,6 +86,9 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds [] func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdioFDs []int) (*hostvfs2.TTYFileDescription, error) { k := kernel.KernelFromContext(ctx) + if k == nil { + return nil, fmt.Errorf("cannot find kernel from context") + } var ttyFile *vfs.FileDescription for appFD, hostFD := range stdioFDs { diff --git a/pkg/sentry/fsimpl/fuse/connection.go b/pkg/sentry/fsimpl/fuse/connection.go index f330da0bd..6df2728ab 100644 --- a/pkg/sentry/fsimpl/fuse/connection.go +++ b/pkg/sentry/fsimpl/fuse/connection.go @@ -17,6 +17,8 @@ package fuse import ( "errors" "fmt" + "sync" + "sync/atomic" "syscall" "gvisor.dev/gvisor/pkg/abi/linux" @@ -25,18 +27,29 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/waiter" "gvisor.dev/gvisor/tools/go_marshal/marshal" ) -// MaxActiveRequestsDefault is the default setting controlling the upper bound +// maxActiveRequestsDefault is the default setting controlling the upper bound // on the number of active requests at any given time. -const MaxActiveRequestsDefault = 10000 +const maxActiveRequestsDefault = 10000 -var ( - // Ordinary requests have even IDs, while interrupts IDs are odd. - InitReqBit uint64 = 1 - ReqIDStep uint64 = 2 +// Ordinary requests have even IDs, while interrupts IDs are odd. +// Used to increment the unique ID for each FUSE request. +var reqIDStep uint64 = 2 + +const ( + // fuseDefaultMaxBackground is the default value for MaxBackground. + fuseDefaultMaxBackground = 12 + + // fuseDefaultCongestionThreshold is the default value for CongestionThreshold, + // and is 75% of the default maximum of MaxGround. + fuseDefaultCongestionThreshold = (fuseDefaultMaxBackground * 3 / 4) + + // fuseDefaultMaxPagesPerReq is the default value for MaxPagesPerReq. + fuseDefaultMaxPagesPerReq = 32 ) // Request represents a FUSE operation request that hasn't been sent to the @@ -61,17 +74,125 @@ type Response struct { data []byte } -// Connection is the struct by which the sentry communicates with the FUSE server daemon. -type Connection struct { +// connection is the struct by which the sentry communicates with the FUSE server daemon. +type connection struct { fd *DeviceFD - // MaxWrite is the daemon's maximum size of a write buffer. - // This is negotiated during FUSE_INIT. - MaxWrite uint32 + // The following FUSE_INIT flags are currently unsupported by this implementation: + // - FUSE_ATOMIC_O_TRUNC: requires open(..., O_TRUNC) + // - FUSE_EXPORT_SUPPORT + // - FUSE_HANDLE_KILLPRIV + // - FUSE_POSIX_LOCKS: requires POSIX locks + // - FUSE_FLOCK_LOCKS: requires POSIX locks + // - FUSE_AUTO_INVAL_DATA: requires page caching eviction + // - FUSE_EXPLICIT_INVAL_DATA: requires page caching eviction + // - FUSE_DO_READDIRPLUS/FUSE_READDIRPLUS_AUTO: requires FUSE_READDIRPLUS implementation + // - FUSE_ASYNC_DIO + // - FUSE_POSIX_ACL: affects defaultPermissions, posixACL, xattr handler + + // initialized after receiving FUSE_INIT reply. + // Until it's set, suspend sending FUSE requests. + // Use SetInitialized() and IsInitialized() for atomic access. + initialized int32 + + // initializedChan is used to block requests before initialization. + initializedChan chan struct{} + + // blocked when there are too many outstading backgrounds requests (NumBackground == MaxBackground). + // TODO(gvisor.dev/issue/3185): update the numBackground accordingly; use a channel to block. + blocked bool + + // connected (connection established) when a new FUSE file system is created. + // Set to false when: + // umount, + // connection abort, + // device release. + connected bool + + // aborted via sysfs. + // TODO(gvisor.dev/issue/3185): abort all queued requests. + aborted bool + + // connInitError if FUSE_INIT encountered error (major version mismatch). + // Only set in INIT. + connInitError bool + + // connInitSuccess if FUSE_INIT is successful. + // Only set in INIT. + // Used for destory. + connInitSuccess bool + + // TODO(gvisor.dev/issue/3185): All the queue logic are working in progress. + + // NumberBackground is the number of requests in the background. + numBackground uint16 + + // congestionThreshold for NumBackground. + // Negotiated in FUSE_INIT. + congestionThreshold uint16 + + // maxBackground is the maximum number of NumBackground. + // Block connection when it is reached. + // Negotiated in FUSE_INIT. + maxBackground uint16 + + // numActiveBackground is the number of requests in background and has being marked as active. + numActiveBackground uint16 + + // numWating is the number of requests waiting for completion. + numWaiting uint32 + + // TODO(gvisor.dev/issue/3185): BgQueue + // some queue for background queued requests. + + // bgLock protects: + // MaxBackground, CongestionThreshold, NumBackground, + // NumActiveBackground, BgQueue, Blocked. + bgLock sync.Mutex + + // maxRead is the maximum size of a read buffer in in bytes. + maxRead uint32 + + // maxWrite is the maximum size of a write buffer in bytes. + // Negotiated in FUSE_INIT. + maxWrite uint32 + + // maxPages is the maximum number of pages for a single request to use. + // Negotiated in FUSE_INIT. + maxPages uint16 + + // minor version of the FUSE protocol. + // Negotiated and only set in INIT. + minor uint32 + + // asyncRead if read pages asynchronously. + // Negotiated and only set in INIT. + asyncRead bool + + // abortErr is true if kernel need to return an unique read error after abort. + // Negotiated and only set in INIT. + abortErr bool + + // writebackCache is true for write-back cache policy, + // false for write-through policy. + // Negotiated and only set in INIT. + writebackCache bool + + // cacheSymlinks if filesystem needs to cache READLINK responses in page cache. + // Negotiated and only set in INIT. + cacheSymlinks bool + + // bigWrites if doing multi-page cached writes. + // Negotiated and only set in INIT. + bigWrites bool + + // dontMask if filestestem does not apply umask to creation modes. + // Negotiated in INIT. + dontMask bool } -// NewFUSEConnection creates a FUSE connection to fd -func NewFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRequests uint64) (*Connection, error) { +// newFUSEConnection creates a FUSE connection to fd. +func newFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRequests uint64) (*connection, error) { // Mark the device as ready so it can be used. /dev/fuse can only be used if the FD was used to // mount a FUSE filesystem. fuseFD := fd.Impl().(*DeviceFD) @@ -84,16 +205,41 @@ func NewFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRe fuseFD.fullQueueCh = make(chan struct{}, maxInFlightRequests) fuseFD.writeCursor = 0 - return &Connection{ - fd: fuseFD, + return &connection{ + fd: fuseFD, + maxBackground: fuseDefaultMaxBackground, + congestionThreshold: fuseDefaultCongestionThreshold, + maxPages: fuseDefaultMaxPagesPerReq, + initializedChan: make(chan struct{}), + connected: true, }, nil } +// SetInitialized atomically sets the connection as initialized. +func (conn *connection) SetInitialized() { + // Unblock the requests sent before INIT. + close(conn.initializedChan) + + // Close the channel first to avoid the non-atomic situation + // where conn.initialized is true but there are + // tasks being blocked on the channel. + // And it prevents the newer tasks from gaining + // unnecessary higher chance to be issued before the blocked one. + + atomic.StoreInt32(&(conn.initialized), int32(1)) +} + +// IsInitialized atomically check if the connection is initialized. +// pairs with SetInitialized(). +func (conn *connection) Initialized() bool { + return atomic.LoadInt32(&(conn.initialized)) != 0 +} + // NewRequest creates a new request that can be sent to the FUSE server. -func (conn *Connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { +func (conn *connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { conn.fd.mu.Lock() defer conn.fd.mu.Unlock() - conn.fd.nextOpID += linux.FUSEOpID(ReqIDStep) + conn.fd.nextOpID += linux.FUSEOpID(reqIDStep) hdrLen := (*linux.FUSEHeaderIn)(nil).SizeBytes() hdr := linux.FUSEHeaderIn{ @@ -118,13 +264,49 @@ func (conn *Connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint } // Call makes a request to the server and blocks the invoking task until a -// server responds with a response. -// NOTE: If no task is provided then the Call will simply enqueue the request -// and return a nil response. No blocking will happen in this case. Instead, -// this is used to signify that the processing of this request will happen by -// the kernel.Task that writes the response. See FUSE_INIT for such an -// invocation. -func (conn *Connection) Call(t *kernel.Task, r *Request) (*Response, error) { +// server responds with a response. Task should never be nil. +// Requests will not be sent before the connection is initialized. +// For async tasks, use CallAsync(). +func (conn *connection) Call(t *kernel.Task, r *Request) (*Response, error) { + // Block requests sent before connection is initalized. + if !conn.Initialized() { + if err := t.Block(conn.initializedChan); err != nil { + return nil, err + } + } + + return conn.call(t, r) +} + +// CallAsync makes an async (aka background) request. +// Those requests either do not expect a response (e.g. release) or +// the response should be handled by others (e.g. init). +// Return immediately unless the connection is blocked (before initialization). +// Async call example: init, release, forget, aio, interrupt. +// When the Request is FUSE_INIT, it will not be blocked before initialization. +func (conn *connection) CallAsync(t *kernel.Task, r *Request) error { + // Block requests sent before connection is initalized. + if !conn.Initialized() && r.hdr.Opcode != linux.FUSE_INIT { + if err := t.Block(conn.initializedChan); err != nil { + return err + } + } + + // This should be the only place that invokes call() with a nil task. + _, err := conn.call(nil, r) + return err +} + +// call makes a call without blocking checks. +func (conn *connection) call(t *kernel.Task, r *Request) (*Response, error) { + if !conn.connected { + return nil, syserror.ENOTCONN + } + + if conn.connInitError { + return nil, syserror.ECONNREFUSED + } + fut, err := conn.callFuture(t, r) if err != nil { return nil, err @@ -160,7 +342,7 @@ func (r *Response) UnmarshalPayload(m marshal.Marshallable) error { // callFuture makes a request to the server and returns a future response. // Call resolve() when the response needs to be fulfilled. -func (conn *Connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, error) { +func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, error) { conn.fd.mu.Lock() defer conn.fd.mu.Unlock() @@ -195,7 +377,7 @@ func (conn *Connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, } // callFutureLocked makes a request to the server and returns a future response. -func (conn *Connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) { +func (conn *connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) { conn.fd.queue.PushBack(r) conn.fd.numActiveRequests += 1 fut := newFutureResponse(r.hdr.Opcode) diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go index f3443ac71..2225076bc 100644 --- a/pkg/sentry/fsimpl/fuse/dev.go +++ b/pkg/sentry/fsimpl/fuse/dev.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" @@ -98,7 +99,9 @@ type DeviceFD struct { } // Release implements vfs.FileDescriptionImpl.Release. -func (fd *DeviceFD) Release() {} +func (fd *DeviceFD) Release() { + fd.fs.conn.connected = false +} // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { @@ -124,7 +127,7 @@ func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.R minBuffSize := linux.FUSE_MIN_READ_BUFFER inHdrLen := uint32((*linux.FUSEHeaderIn)(nil).SizeBytes()) writeHdrLen := uint32((*linux.FUSEWriteIn)(nil).SizeBytes()) - negotiatedMinBuffSize := inHdrLen + writeHdrLen + fd.fs.conn.MaxWrite + negotiatedMinBuffSize := inHdrLen + writeHdrLen + fd.fs.conn.maxWrite if minBuffSize < negotiatedMinBuffSize { minBuffSize = negotiatedMinBuffSize } @@ -385,9 +388,9 @@ func (fd *DeviceFD) sendError(ctx context.Context, errno int32, req *Request) er // FUSE_INIT. func (fd *DeviceFD) noReceiverAction(ctx context.Context, r *Response) error { if r.opcode == linux.FUSE_INIT { - // TODO: process init response here. - // Maybe get the creds from the context? - // creds := auth.CredentialsFromContext(ctx) + creds := auth.CredentialsFromContext(ctx) + rootUserNs := kernel.KernelFromContext(ctx).RootUserNamespace() + return fd.fs.conn.InitRecv(r, creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, rootUserNs)) } return nil diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 911b6f7cb..200a93bbf 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -65,7 +65,7 @@ type filesystem struct { // conn is used for communication between the FUSE server // daemon and the sentry fusefs. - conn *Connection + conn *connection // opts is the options the fusefs is initialized with. opts *filesystemOptions @@ -140,7 +140,7 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fsopts.rootMode = rootMode // Set the maxInFlightRequests option. - fsopts.maxActiveRequests = MaxActiveRequestsDefault + fsopts.maxActiveRequests = maxActiveRequestsDefault // Check for unparsed options. if len(mopts) != 0 { @@ -157,8 +157,12 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fs.VFSFilesystem().Init(vfsObj, &fsType, fs) - // TODO: dispatch a FUSE_INIT request to the FUSE daemon server before - // returning. Mount will not block on this dispatched request. + // Send a FUSE_INIT request to the FUSE daemon server before returning. + // This call is not blocking. + if err := fs.conn.InitSend(creds, uint32(kernelTask.ThreadID())); err != nil { + log.Warningf("%s.InitSend: failed with error: %v", fsType.Name(), err) + return nil, nil, err + } // root is the fusefs root directory. root := fs.newInode(creds, fsopts.rootMode) @@ -173,7 +177,7 @@ func NewFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOpt opts: opts, } - conn, err := NewFUSEConnection(ctx, device, opts.maxActiveRequests) + conn, err := newFUSEConnection(ctx, device, opts.maxActiveRequests) if err != nil { log.Warningf("fuse.NewFUSEFilesystem: NewFUSEConnection failed with error: %v", err) return nil, syserror.EINVAL @@ -192,8 +196,8 @@ func (fs *filesystem) Release() { fs.Filesystem.Release() } -// Inode implements kernfs.Inode. -type Inode struct { +// inode implements kernfs.Inode. +type inode struct { kernfs.InodeAttrs kernfs.InodeNoDynamicLookup kernfs.InodeNotSymlink @@ -206,7 +210,7 @@ type Inode struct { } func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *kernfs.Dentry { - i := &Inode{} + i := &inode{} i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) i.dentry.Init(i) @@ -215,7 +219,7 @@ func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *ke } // Open implements kernfs.Inode.Open. -func (i *Inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts) if err != nil { return nil, err diff --git a/pkg/sentry/fsimpl/fuse/init.go b/pkg/sentry/fsimpl/fuse/init.go new file mode 100644 index 000000000..779c2bd3f --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/init.go @@ -0,0 +1,166 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" +) + +// consts used by FUSE_INIT negotiation. +const ( + // fuseMaxMaxPages is the maximum value for MaxPages received in InitOut. + // Follow the same behavior as unix fuse implementation. + fuseMaxMaxPages = 256 + + // Maximum value for the time granularity for file time stamps, 1s. + // Follow the same behavior as unix fuse implementation. + fuseMaxTimeGranNs = 1000000000 + + // Minimum value for MaxWrite. + // Follow the same behavior as unix fuse implementation. + fuseMinMaxWrite = 4096 + + // Temporary default value for max readahead, 128kb. + fuseDefaultMaxReadahead = 131072 + + // The FUSE_INIT_IN flags sent to the daemon. + // TODO(gvisor.dev/issue/3199): complete the flags. + fuseDefaultInitFlags = linux.FUSE_MAX_PAGES +) + +// Adjustable maximums for Connection's cogestion control parameters. +// Used as the upperbound of the config values. +// Currently we do not support adjustment to them. +var ( + MaxUserBackgroundRequest uint16 = fuseDefaultMaxBackground + MaxUserCongestionThreshold uint16 = fuseDefaultCongestionThreshold +) + +// InitSend sends a FUSE_INIT request. +func (conn *connection) InitSend(creds *auth.Credentials, pid uint32) error { + in := linux.FUSEInitIn{ + Major: linux.FUSE_KERNEL_VERSION, + Minor: linux.FUSE_KERNEL_MINOR_VERSION, + // TODO(gvisor.dev/issue/3196): find appropriate way to calculate this + MaxReadahead: fuseDefaultMaxReadahead, + Flags: fuseDefaultInitFlags, + } + + req, err := conn.NewRequest(creds, pid, 0, linux.FUSE_INIT, &in) + if err != nil { + return err + } + + // Since there is no task to block on and FUSE_INIT is the request + // to unblock other requests, use nil. + return conn.CallAsync(nil, req) +} + +// InitRecv receives a FUSE_INIT reply and process it. +func (conn *connection) InitRecv(res *Response, hasSysAdminCap bool) error { + if err := res.Error(); err != nil { + return err + } + + var out linux.FUSEInitOut + if err := res.UnmarshalPayload(&out); err != nil { + return err + } + + return conn.initProcessReply(&out, hasSysAdminCap) +} + +// Process the FUSE_INIT reply from the FUSE server. +func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap bool) error { + // No support for old major fuse versions. + if out.Major != linux.FUSE_KERNEL_VERSION { + conn.connInitError = true + + // Set the connection as initialized and unblock the blocked requests + // (i.e. return error for them). + conn.SetInitialized() + + return nil + } + + // Start processing the reply. + conn.connInitSuccess = true + conn.minor = out.Minor + + // No support for limits before minor version 13. + if out.Minor >= 13 { + conn.bgLock.Lock() + + if out.MaxBackground > 0 { + conn.maxBackground = out.MaxBackground + + if !hasSysAdminCap && + conn.maxBackground > MaxUserBackgroundRequest { + conn.maxBackground = MaxUserBackgroundRequest + } + } + + if out.CongestionThreshold > 0 { + conn.congestionThreshold = out.CongestionThreshold + + if !hasSysAdminCap && + conn.congestionThreshold > MaxUserCongestionThreshold { + conn.congestionThreshold = MaxUserCongestionThreshold + } + } + + conn.bgLock.Unlock() + } + + // No support for the following flags before minor version 6. + if out.Minor >= 6 { + conn.asyncRead = out.Flags&linux.FUSE_ASYNC_READ != 0 + conn.bigWrites = out.Flags&linux.FUSE_BIG_WRITES != 0 + conn.dontMask = out.Flags&linux.FUSE_DONT_MASK != 0 + conn.writebackCache = out.Flags&linux.FUSE_WRITEBACK_CACHE != 0 + conn.cacheSymlinks = out.Flags&linux.FUSE_CACHE_SYMLINKS != 0 + conn.abortErr = out.Flags&linux.FUSE_ABORT_ERROR != 0 + + // TODO(gvisor.dev/issue/3195): figure out how to use TimeGran (0 < TimeGran <= fuseMaxTimeGranNs). + + if out.Flags&linux.FUSE_MAX_PAGES != 0 { + maxPages := out.MaxPages + if maxPages < 1 { + maxPages = 1 + } + if maxPages > fuseMaxMaxPages { + maxPages = fuseMaxMaxPages + } + conn.maxPages = maxPages + } + } + + // No support for negotiating MaxWrite before minor version 5. + if out.Minor >= 5 { + conn.maxWrite = out.MaxWrite + } else { + conn.maxWrite = fuseMinMaxWrite + } + if conn.maxWrite < fuseMinMaxWrite { + conn.maxWrite = fuseMinMaxWrite + } + + // Set connection as initialized and unblock the requests + // issued before init. + conn.SetInitialized() + + return nil +} diff --git a/pkg/sentry/platform/kvm/kvm_const_arm64.go b/pkg/sentry/platform/kvm/kvm_const_arm64.go index 6f0539c29..fdc599477 100644 --- a/pkg/sentry/platform/kvm/kvm_const_arm64.go +++ b/pkg/sentry/platform/kvm/kvm_const_arm64.go @@ -116,6 +116,17 @@ const ( // Arm64: Exception Syndrome Register EL1. const ( + _ESR_ELx_EC_SHIFT = 26 + _ESR_ELx_EC_MASK = 0x3F << _ESR_ELx_EC_SHIFT + + _ESR_ELx_EC_IMP_DEF = 0x1f + _ESR_ELx_EC_IABT_LOW = 0x20 + _ESR_ELx_EC_IABT_CUR = 0x21 + _ESR_ELx_EC_PC_ALIGN = 0x22 + + _ESR_ELx_CM = 1 << 8 + _ESR_ELx_WNR = 1 << 6 + _ESR_ELx_FSC = 0x3F _ESR_SEGV_MAPERR_L0 = 0x4 diff --git a/pkg/sentry/platform/kvm/machine_arm64.go b/pkg/sentry/platform/kvm/machine_arm64.go index f3bf973de..9db171af9 100644 --- a/pkg/sentry/platform/kvm/machine_arm64.go +++ b/pkg/sentry/platform/kvm/machine_arm64.go @@ -125,71 +125,59 @@ func nonCanonical(addr uint64, signal int32, info *arch.SignalInfo) (usermem.Acc return usermem.NoAccess, platform.ErrContextSignal } +// isInstructionAbort returns true if it is an instruction abort. +// +//go:nosplit +func isInstructionAbort(code uint64) bool { + value := (code & _ESR_ELx_EC_MASK) >> _ESR_ELx_EC_SHIFT + return value == _ESR_ELx_EC_IABT_LOW +} + +// isWriteFault returns whether it is a write fault. +// +//go:nosplit +func isWriteFault(code uint64) bool { + if isInstructionAbort(code) { + return false + } + + return (code & _ESR_ELx_WNR) != 0 +} + // fault generates an appropriate fault return. // //go:nosplit func (c *vCPU) fault(signal int32, info *arch.SignalInfo) (usermem.AccessType, error) { + bluepill(c) // Probably no-op, but may not be. faultAddr := c.GetFaultAddr() code, user := c.ErrorCode() + if !user { + // The last fault serviced by this CPU was not a user + // fault, so we can't reliably trust the faultAddr or + // the code provided here. We need to re-execute. + return usermem.NoAccess, platform.ErrContextInterrupt + } + // Reset the pointed SignalInfo. *info = arch.SignalInfo{Signo: signal} info.SetAddr(uint64(faultAddr)) - read := true - write := false - execute := true - ret := code & _ESR_ELx_FSC switch ret { case _ESR_SEGV_MAPERR_L0, _ESR_SEGV_MAPERR_L1, _ESR_SEGV_MAPERR_L2, _ESR_SEGV_MAPERR_L3: info.Code = 1 //SEGV_MAPERR - read = false - write = true - execute = false case _ESR_SEGV_ACCERR_L1, _ESR_SEGV_ACCERR_L2, _ESR_SEGV_ACCERR_L3, _ESR_SEGV_PEMERR_L1, _ESR_SEGV_PEMERR_L2, _ESR_SEGV_PEMERR_L3: info.Code = 2 // SEGV_ACCERR. - read = true - write = false - execute = false default: info.Code = 2 } - if !user { - read = true - write = false - execute = true - - } accessType := usermem.AccessType{ - Read: read, - Write: write, - Execute: execute, + Read: !isWriteFault(uint64(code)), + Write: isWriteFault(uint64(code)), + Execute: isInstructionAbort(uint64(code)), } return accessType, platform.ErrContextSignal } - -// retryInGuest runs the given function in guest mode. -// -// If the function does not complete in guest mode (due to execution of a -// system call due to a GC stall, for example), then it will be retried. The -// given function must be idempotent as a result of the retry mechanism. -func (m *machine) retryInGuest(fn func()) { - c := m.Get() - defer m.Put(c) - for { - c.ClearErrorCode() // See below. - bluepill(c) // Force guest mode. - fn() // Execute the given function. - _, user := c.ErrorCode() - if user { - // If user is set, then we haven't bailed back to host - // mode via a kernel exception or system call. We - // consider the full function to have executed in guest - // mode and we can return. - break - } - } -} diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 44b3fff46..31a168f7e 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -423,7 +423,7 @@ func AddressAndFamily(addr []byte) (tcpip.FullAddress, uint16, *syserr.Error) { return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument } - // TODO(b/129292371): Return protocol too. + // TODO(gvisor.dev/issue/173): Return protocol too. return tcpip.FullAddress{ NIC: tcpip.NICID(a.InterfaceIndex), Addr: tcpip.Address(a.HardwareAddr[:header.EthernetAddressSize]), @@ -1490,6 +1490,10 @@ func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (marsha vP := primitive.Int32(boolToInt32(v)) return &vP, nil + case linux.SO_ORIGINAL_DST: + // TODO(gvisor.dev/issue/170): ip6tables. + return nil, syserr.ErrInvalidArgument + default: emitUnimplementedEventIPv6(t, name) } @@ -1600,6 +1604,19 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int, family in vP := primitive.Int32(boolToInt32(v)) return &vP, nil + case linux.SO_ORIGINAL_DST: + if outLen < int(binary.Size(linux.SockAddrInet{})) { + return nil, syserr.ErrInvalidArgument + } + + var v tcpip.OriginalDestinationOption + if err := ep.GetSockOpt(&v); err != nil { + return nil, syserr.TranslateNetstackError(err) + } + + a, _ := ConvertAddress(linux.AF_INET, tcpip.FullAddress(v)) + return a.(*linux.SockAddrInet), nil + default: emitUnimplementedEventIP(t, name) } @@ -2418,7 +2435,7 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) return &out, uint32(sockAddrInet6Size) case linux.AF_PACKET: - // TODO(b/129292371): Return protocol too. + // TODO(gvisor.dev/issue/173): Return protocol too. var out linux.SockAddrLink out.Family = linux.AF_PACKET out.InterfaceIndex = int32(addr.NIC) diff --git a/pkg/sentry/strace/socket.go b/pkg/sentry/strace/socket.go index c0512de89..b51c4c941 100644 --- a/pkg/sentry/strace/socket.go +++ b/pkg/sentry/strace/socket.go @@ -521,6 +521,7 @@ var sockOptNames = map[uint64]abi.ValueSet{ linux.IP_ROUTER_ALERT: "IP_ROUTER_ALERT", linux.IP_PKTOPTIONS: "IP_PKTOPTIONS", linux.IP_MTU: "IP_MTU", + linux.SO_ORIGINAL_DST: "SO_ORIGINAL_DST", }, linux.SOL_SOCKET: { linux.SO_ERROR: "SO_ERROR", diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go index 2797c6a72..8cf6401e7 100644 --- a/pkg/sentry/syscalls/linux/sys_file.go +++ b/pkg/sentry/syscalls/linux/sys_file.go @@ -1057,7 +1057,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.F_SETOWN_EX: addr := args[2].Pointer() var owner linux.FOwnerEx - n, err := t.CopyIn(addr, &owner) + _, err := t.CopyIn(addr, &owner) if err != nil { return 0, nil, err } @@ -1069,21 +1069,21 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return 0, nil, syserror.ESRCH } a.SetOwnerTask(t, task) - return uintptr(n), nil, nil + return 0, nil, nil case linux.F_OWNER_PID: tg := t.PIDNamespace().ThreadGroupWithID(kernel.ThreadID(owner.PID)) if tg == nil { return 0, nil, syserror.ESRCH } a.SetOwnerThreadGroup(t, tg) - return uintptr(n), nil, nil + return 0, nil, nil case linux.F_OWNER_PGRP: pg := t.PIDNamespace().ProcessGroupWithID(kernel.ProcessGroupID(owner.PID)) if pg == nil { return 0, nil, syserror.ESRCH } a.SetOwnerProcessGroup(t, pg) - return uintptr(n), nil, nil + return 0, nil, nil default: return 0, nil, syserror.EINVAL } diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go index 517394ba9..67f191551 100644 --- a/pkg/sentry/syscalls/linux/vfs2/fd.go +++ b/pkg/sentry/syscalls/linux/vfs2/fd.go @@ -185,11 +185,11 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return 0, nil, err case linux.F_SETOWN_EX: var owner linux.FOwnerEx - n, err := t.CopyIn(args[2].Pointer(), &owner) + _, err := t.CopyIn(args[2].Pointer(), &owner) if err != nil { return 0, nil, err } - return uintptr(n), nil, setAsyncOwner(t, file, owner.Type, owner.PID) + return 0, nil, setAsyncOwner(t, file, owner.Type, owner.PID) case linux.F_GETPIPE_SZ: pipefile, ok := file.Impl().(*pipe.VFSPipeFD) if !ok { diff --git a/pkg/sentry/syscalls/linux/vfs2/filesystem.go b/pkg/sentry/syscalls/linux/vfs2/filesystem.go index 6b14c2bef..b6d2ddd65 100644 --- a/pkg/sentry/syscalls/linux/vfs2/filesystem.go +++ b/pkg/sentry/syscalls/linux/vfs2/filesystem.go @@ -18,7 +18,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -245,55 +244,6 @@ func renameat(t *kernel.Task, olddirfd int32, oldpathAddr usermem.Addr, newdirfd }) } -// Fallocate implements linux system call fallocate(2). -func Fallocate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { - fd := args[0].Int() - mode := args[1].Uint64() - offset := args[2].Int64() - length := args[3].Int64() - - file := t.GetFileVFS2(fd) - - if file == nil { - return 0, nil, syserror.EBADF - } - defer file.DecRef() - - if !file.IsWritable() { - return 0, nil, syserror.EBADF - } - - if mode != 0 { - return 0, nil, syserror.ENOTSUP - } - - if offset < 0 || length <= 0 { - return 0, nil, syserror.EINVAL - } - - size := offset + length - - if size < 0 { - return 0, nil, syserror.EFBIG - } - - limit := limits.FromContext(t).Get(limits.FileSize).Cur - - if uint64(size) >= limit { - t.SendSignal(&arch.SignalInfo{ - Signo: int32(linux.SIGXFSZ), - Code: arch.SignalInfoUser, - }) - return 0, nil, syserror.EFBIG - } - - return 0, nil, file.Impl().Allocate(t, mode, uint64(offset), uint64(length)) - - // File length modified, generate notification. - // TODO(gvisor.dev/issue/1479): Reenable when Inotify is ported. - // file.Dirent.InotifyEvent(linux.IN_MODIFY, 0) -} - // Rmdir implements Linux syscall rmdir(2). func Rmdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() diff --git a/pkg/sentry/syscalls/linux/vfs2/setstat.go b/pkg/sentry/syscalls/linux/vfs2/setstat.go index 6daedd173..37fa56c19 100644 --- a/pkg/sentry/syscalls/linux/vfs2/setstat.go +++ b/pkg/sentry/syscalls/linux/vfs2/setstat.go @@ -20,6 +20,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -211,6 +212,55 @@ func Ftruncate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, handleSetSizeError(t, err) } +// Fallocate implements linux system call fallocate(2). +func Fallocate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + fd := args[0].Int() + mode := args[1].Uint64() + offset := args[2].Int64() + length := args[3].Int64() + + file := t.GetFileVFS2(fd) + + if file == nil { + return 0, nil, syserror.EBADF + } + defer file.DecRef() + + if !file.IsWritable() { + return 0, nil, syserror.EBADF + } + + if mode != 0 { + return 0, nil, syserror.ENOTSUP + } + + if offset < 0 || length <= 0 { + return 0, nil, syserror.EINVAL + } + + size := offset + length + + if size < 0 { + return 0, nil, syserror.EFBIG + } + + limit := limits.FromContext(t).Get(limits.FileSize).Cur + + if uint64(size) >= limit { + t.SendSignal(&arch.SignalInfo{ + Signo: int32(linux.SIGXFSZ), + Code: arch.SignalInfoUser, + }) + return 0, nil, syserror.EFBIG + } + + return 0, nil, file.Allocate(t, mode, uint64(offset), uint64(length)) + + // File length modified, generate notification. + // TODO(gvisor.dev/issue/1479): Reenable when Inotify is ported. + // file.Dirent.InotifyEvent(linux.IN_MODIFY, 0) +} + // Utime implements Linux syscall utime(2). func Utime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go index 599c3131c..5b009b928 100644 --- a/pkg/sentry/vfs/epoll.go +++ b/pkg/sentry/vfs/epoll.go @@ -186,7 +186,7 @@ func (ep *EpollInstance) AddInterest(file *FileDescription, num int32, event lin } // Register interest in file. - mask := event.Events | linux.EPOLLERR | linux.EPOLLRDHUP + mask := event.Events | linux.EPOLLERR | linux.EPOLLHUP epi := &epollInterest{ epoll: ep, key: key, @@ -257,7 +257,7 @@ func (ep *EpollInstance) ModifyInterest(file *FileDescription, num int32, event } // Update epi for the next call to ep.ReadEvents(). - mask := event.Events | linux.EPOLLERR | linux.EPOLLRDHUP + mask := event.Events | linux.EPOLLERR | linux.EPOLLHUP ep.mu.Lock() epi.mask = mask epi.userData = event.Data diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 0c42574db..93861fb4a 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -354,7 +354,7 @@ type FileDescriptionImpl interface { // represented by the FileDescription. StatFS(ctx context.Context) (linux.Statfs, error) - // Allocate grows file represented by FileDescription to offset + length bytes. + // Allocate grows the file to offset + length bytes. // Only mode == 0 is supported currently. Allocate(ctx context.Context, mode, offset, length uint64) error @@ -563,6 +563,11 @@ func (fd *FileDescription) StatFS(ctx context.Context) (linux.Statfs, error) { return fd.impl.StatFS(ctx) } +// Allocate grows file represented by FileDescription to offset + length bytes. +func (fd *FileDescription) Allocate(ctx context.Context, mode, offset, length uint64) error { + return fd.impl.Allocate(ctx, mode, offset, length) +} + // Readiness implements waiter.Waitable.Readiness. // // It returns fd's I/O readiness. diff --git a/pkg/syserror/syserror.go b/pkg/syserror/syserror.go index c73072c42..798e07b01 100644 --- a/pkg/syserror/syserror.go +++ b/pkg/syserror/syserror.go @@ -61,6 +61,7 @@ var ( ENOMEM = error(syscall.ENOMEM) ENOSPC = error(syscall.ENOSPC) ENOSYS = error(syscall.ENOSYS) + ENOTCONN = error(syscall.ENOTCONN) ENOTDIR = error(syscall.ENOTDIR) ENOTEMPTY = error(syscall.ENOTEMPTY) ENOTSOCK = error(syscall.ENOTSOCK) diff --git a/pkg/tcpip/network/fragmentation/fragmentation.go b/pkg/tcpip/network/fragmentation/fragmentation.go index 2982450f8..1827666c5 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation.go +++ b/pkg/tcpip/network/fragmentation/fragmentation.go @@ -17,28 +17,58 @@ package fragmentation import ( + "errors" "fmt" "log" "time" "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" ) -// DefaultReassembleTimeout is based on the linux stack: net.ipv4.ipfrag_time. -const DefaultReassembleTimeout = 30 * time.Second +const ( + // DefaultReassembleTimeout is based on the linux stack: net.ipv4.ipfrag_time. + DefaultReassembleTimeout = 30 * time.Second -// HighFragThreshold is the threshold at which we start trimming old -// fragmented packets. Linux uses a default value of 4 MB. See -// net.ipv4.ipfrag_high_thresh for more information. -const HighFragThreshold = 4 << 20 // 4MB + // HighFragThreshold is the threshold at which we start trimming old + // fragmented packets. Linux uses a default value of 4 MB. See + // net.ipv4.ipfrag_high_thresh for more information. + HighFragThreshold = 4 << 20 // 4MB -// LowFragThreshold is the threshold we reach to when we start dropping -// older fragmented packets. It's important that we keep enough room for newer -// packets to be re-assembled. Hence, this needs to be lower than -// HighFragThreshold enough. Linux uses a default value of 3 MB. See -// net.ipv4.ipfrag_low_thresh for more information. -const LowFragThreshold = 3 << 20 // 3MB + // LowFragThreshold is the threshold we reach to when we start dropping + // older fragmented packets. It's important that we keep enough room for newer + // packets to be re-assembled. Hence, this needs to be lower than + // HighFragThreshold enough. Linux uses a default value of 3 MB. See + // net.ipv4.ipfrag_low_thresh for more information. + LowFragThreshold = 3 << 20 // 3MB + + // minBlockSize is the minimum block size for fragments. + minBlockSize = 1 +) + +var ( + // ErrInvalidArgs indicates to the caller that that an invalid argument was + // provided. + ErrInvalidArgs = errors.New("invalid args") +) + +// FragmentID is the identifier for a fragment. +type FragmentID struct { + // Source is the source address of the fragment. + Source tcpip.Address + + // Destination is the destination address of the fragment. + Destination tcpip.Address + + // ID is the identification value of the fragment. + // + // This is a uint32 because IPv6 uses a 32-bit identification value. + ID uint32 + + // The protocol for the packet. + Protocol uint8 +} // Fragmentation is the main structure that other modules // of the stack should use to implement IP Fragmentation. @@ -46,14 +76,17 @@ type Fragmentation struct { mu sync.Mutex highLimit int lowLimit int - reassemblers map[uint32]*reassembler + reassemblers map[FragmentID]*reassembler rList reassemblerList size int timeout time.Duration + blockSize uint16 } // NewFragmentation creates a new Fragmentation. // +// blockSize specifies the fragment block size, in bytes. +// // highMemoryLimit specifies the limit on the memory consumed // by the fragments stored by Fragmentation (overhead of internal data-structures // is not accounted). Fragments are dropped when the limit is reached. @@ -64,7 +97,7 @@ type Fragmentation struct { // reassemblingTimeout specifies the maximum time allowed to reassemble a packet. // Fragments are lazily evicted only when a new a packet with an // already existing fragmentation-id arrives after the timeout. -func NewFragmentation(highMemoryLimit, lowMemoryLimit int, reassemblingTimeout time.Duration) *Fragmentation { +func NewFragmentation(blockSize uint16, highMemoryLimit, lowMemoryLimit int, reassemblingTimeout time.Duration) *Fragmentation { if lowMemoryLimit >= highMemoryLimit { lowMemoryLimit = highMemoryLimit } @@ -73,17 +106,46 @@ func NewFragmentation(highMemoryLimit, lowMemoryLimit int, reassemblingTimeout t lowMemoryLimit = 0 } + if blockSize < minBlockSize { + blockSize = minBlockSize + } + return &Fragmentation{ - reassemblers: make(map[uint32]*reassembler), + reassemblers: make(map[FragmentID]*reassembler), highLimit: highMemoryLimit, lowLimit: lowMemoryLimit, timeout: reassemblingTimeout, + blockSize: blockSize, } } // Process processes an incoming fragment belonging to an ID and returns a // complete packet when all the packets belonging to that ID have been received. -func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, error) { +// +// [first, last] is the range of the fragment bytes. +// +// first must be a multiple of the block size f is configured with. The size +// of the fragment data must be a multiple of the block size, unless there are +// no fragments following this fragment (more set to false). +func (f *Fragmentation) Process(id FragmentID, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, error) { + if first > last { + return buffer.VectorisedView{}, false, fmt.Errorf("first=%d is greater than last=%d: %w", first, last, ErrInvalidArgs) + } + + if first%f.blockSize != 0 { + return buffer.VectorisedView{}, false, fmt.Errorf("first=%d is not a multiple of block size=%d: %w", first, f.blockSize, ErrInvalidArgs) + } + + fragmentSize := last - first + 1 + if more && fragmentSize%f.blockSize != 0 { + return buffer.VectorisedView{}, false, fmt.Errorf("fragment size=%d bytes is not a multiple of block size=%d on non-final fragment: %w", fragmentSize, f.blockSize, ErrInvalidArgs) + } + + if l := vv.Size(); l < int(fragmentSize) { + return buffer.VectorisedView{}, false, fmt.Errorf("got fragment size=%d bytes less than the expected fragment size=%d bytes (first=%d last=%d): %w", l, fragmentSize, first, last, ErrInvalidArgs) + } + vv.CapLength(int(fragmentSize)) + f.mu.Lock() r, ok := f.reassemblers[id] if ok && r.tooOld(f.timeout) { diff --git a/pkg/tcpip/network/fragmentation/reassembler.go b/pkg/tcpip/network/fragmentation/reassembler.go index 0a83d81f2..50d30bbf0 100644 --- a/pkg/tcpip/network/fragmentation/reassembler.go +++ b/pkg/tcpip/network/fragmentation/reassembler.go @@ -32,7 +32,7 @@ type hole struct { type reassembler struct { reassemblerEntry - id uint32 + id FragmentID size int mu sync.Mutex holes []hole @@ -42,7 +42,7 @@ type reassembler struct { creationTime time.Time } -func newReassembler(id uint32) *reassembler { +func newReassembler(id FragmentID) *reassembler { r := &reassembler{ id: id, holes: make([]hole, 0, 16), diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index b1776e5ee..d5f5d38f7 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -45,6 +45,10 @@ const ( // buckets is the number of identifier buckets. buckets = 2048 + + // The size of a fragment block, in bytes, as per RFC 791 section 3.1, + // page 14. + fragmentblockSize = 8 ) type endpoint struct { @@ -66,7 +70,7 @@ func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWi prefixLen: addrWithPrefix.PrefixLen, linkEP: linkEP, dispatcher: dispatcher, - fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), + fragmentation: fragmentation.NewFragmentation(fragmentblockSize, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), protocol: p, stack: st, } @@ -438,7 +442,18 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { } var ready bool var err error - pkt.Data, ready, err = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, h.More(), pkt.Data) + pkt.Data, ready, err = e.fragmentation.Process( + fragmentation.FragmentID{ + Source: h.SourceAddress(), + Destination: h.DestinationAddress(), + ID: uint32(h.ID()), + Protocol: h.Protocol(), + }, + h.FragmentOffset(), + last, + h.More(), + pkt.Data, + ) if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 95fbcf2d1..a0a5c9c01 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -28,7 +28,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/network/fragmentation" - "gvisor.dev/gvisor/pkg/tcpip/network/hash" "gvisor.dev/gvisor/pkg/tcpip/stack" ) @@ -343,7 +342,19 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { var ready bool // Note that pkt doesn't have its transport header set after reassembly, // and won't until DeliverNetworkPacket sets it. - pkt.Data, ready, err = e.fragmentation.Process(hash.IPv6FragmentHash(h, extHdr.ID()), start, last, extHdr.More(), rawPayload.Buf) + pkt.Data, ready, err = e.fragmentation.Process( + // IPv6 ignores the Protocol field since the ID only needs to be unique + // across source-destination pairs, as per RFC 8200 section 4.5. + fragmentation.FragmentID{ + Source: h.SourceAddress(), + Destination: h.DestinationAddress(), + ID: extHdr.ID(), + }, + start, + last, + extHdr.More(), + rawPayload.Buf, + ) if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() @@ -467,7 +478,7 @@ func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWi linkEP: linkEP, linkAddrCache: linkAddrCache, dispatcher: dispatcher, - fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), + fragmentation: fragmentation.NewFragmentation(header.IPv6FragmentExtHdrFragmentOffsetBytesPerUnit, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), protocol: p, }, nil } diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go index 559a1c4dd..470c265aa 100644 --- a/pkg/tcpip/stack/conntrack.go +++ b/pkg/tcpip/stack/conntrack.go @@ -240,7 +240,10 @@ func (ct *ConnTrack) connFor(pkt *PacketBuffer) (*conn, direction) { if err != nil { return nil, dirOriginal } + return ct.connForTID(tid) +} +func (ct *ConnTrack) connForTID(tid tupleID) (*conn, direction) { bucket := ct.bucket(tid) now := time.Now() @@ -604,3 +607,26 @@ func (ct *ConnTrack) reapTupleLocked(tuple *tuple, bucket int, now time.Time) bo return true } + +func (ct *ConnTrack) originalDst(epID TransportEndpointID) (tcpip.Address, uint16, *tcpip.Error) { + // Lookup the connection. The reply's original destination + // describes the original address. + tid := tupleID{ + srcAddr: epID.LocalAddress, + srcPort: epID.LocalPort, + dstAddr: epID.RemoteAddress, + dstPort: epID.RemotePort, + transProto: header.TCPProtocolNumber, + netProto: header.IPv4ProtocolNumber, + } + conn, _ := ct.connForTID(tid) + if conn == nil { + // Not a tracked connection. + return "", 0, tcpip.ErrNotConnected + } else if conn.manip == manipNone { + // Unmanipulated connection. + return "", 0, tcpip.ErrInvalidOptionValue + } + + return conn.original.dstAddr, conn.original.dstPort, nil +} diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index cbbae4224..110ba073d 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -218,19 +218,16 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, addr // Many users never configure iptables. Spare them the cost of rule // traversal if rules have never been set. it.mu.RLock() + defer it.mu.RUnlock() if !it.modified { - it.mu.RUnlock() return true } - it.mu.RUnlock() // Packets are manipulated only if connection and matching // NAT rule exists. shouldTrack := it.connections.handlePacket(pkt, hook, gso, r) // Go through each table containing the hook. - it.mu.RLock() - defer it.mu.RUnlock() priorities := it.priorities[hook] for _, tableID := range priorities { // If handlePacket already NATed the packet, we don't need to @@ -418,3 +415,9 @@ func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx // All the matchers matched, so run the target. return rule.Target.Action(pkt, &it.connections, hook, gso, r, address) } + +// OriginalDst returns the original destination of redirected connections. It +// returns an error if the connection doesn't exist or isn't redirected. +func (it *IPTables) OriginalDst(epID TransportEndpointID) (tcpip.Address, uint16, *tcpip.Error) { + return it.connections.originalDst(epID) +} diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 9dce11a97..5174e639c 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -33,12 +33,6 @@ const ( // Default = 1 (from RFC 4862 section 5.1) defaultDupAddrDetectTransmits = 1 - // defaultRetransmitTimer is the default amount of time to wait between - // sending NDP Neighbor solicitation messages. - // - // Default = 1s (from RFC 4861 section 10). - defaultRetransmitTimer = time.Second - // defaultMaxRtrSolicitations is the default number of Router // Solicitation messages to send when a NIC becomes enabled. // @@ -79,16 +73,6 @@ const ( // Default = true. defaultAutoGenGlobalAddresses = true - // minimumRetransmitTimer is the minimum amount of time to wait between - // sending NDP Neighbor solicitation messages. Note, RFC 4861 does - // not impose a minimum Retransmit Timer, but we do here to make sure - // the messages are not sent all at once. We also come to this value - // because in the RetransmitTimer field of a Router Advertisement, a - // value of 0 means unspecified, so the smallest valid value is 1. - // Note, the unit of the RetransmitTimer field in the Router - // Advertisement is milliseconds. - minimumRetransmitTimer = time.Millisecond - // minimumRtrSolicitationInterval is the minimum amount of time to wait // between sending Router Solicitation messages. This limit is imposed // to make sure that Router Solicitation messages are not sent all at diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go new file mode 100644 index 000000000..1d37716c2 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_cache.go @@ -0,0 +1,335 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "fmt" + "time" + + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/tcpip" +) + +const neighborCacheSize = 512 // max entries per interface + +// neighborCache maps IP addresses to link addresses. It uses the Least +// Recently Used (LRU) eviction strategy to implement a bounded cache for +// dynmically acquired entries. It contains the state machine and configuration +// for running Neighbor Unreachability Detection (NUD). +// +// There are two types of entries in the neighbor cache: +// 1. Dynamic entries are discovered automatically by neighbor discovery +// protocols (e.g. ARP, NDP). These protocols will attempt to reconfirm +// reachability with the device once the entry's state becomes Stale. +// 2. Static entries are explicitly added by a user and have no expiration. +// Their state is always Static. The amount of static entries stored in the +// cache is unbounded. +// +// neighborCache implements NUDHandler. +type neighborCache struct { + nic *NIC + state *NUDState + + // mu protects the fields below. + mu sync.RWMutex + + cache map[tcpip.Address]*neighborEntry + dynamic struct { + lru neighborEntryList + + // count tracks the amount of dynamic entries in the cache. This is + // needed since static entries do not count towards the LRU cache + // eviction strategy. + count uint16 + } +} + +var _ NUDHandler = (*neighborCache)(nil) + +// getOrCreateEntry retrieves a cache entry associated with addr. The +// returned entry is always refreshed in the cache (it is reachable via the +// map, and its place is bumped in LRU). +// +// If a matching entry exists in the cache, it is returned. If no matching +// entry exists and the cache is full, an existing entry is evicted via LRU, +// reset to state incomplete, and returned. If no matching entry exists and the +// cache is not full, a new entry with state incomplete is allocated and +// returned. +func (n *neighborCache) getOrCreateEntry(remoteAddr, localAddr tcpip.Address, linkRes LinkAddressResolver) *neighborEntry { + n.mu.Lock() + defer n.mu.Unlock() + + if entry, ok := n.cache[remoteAddr]; ok { + entry.mu.RLock() + if entry.neigh.State != Static { + n.dynamic.lru.Remove(entry) + n.dynamic.lru.PushFront(entry) + } + entry.mu.RUnlock() + return entry + } + + // The entry that needs to be created must be dynamic since all static + // entries are directly added to the cache via addStaticEntry. + entry := newNeighborEntry(n.nic, remoteAddr, localAddr, n.state, linkRes) + if n.dynamic.count == neighborCacheSize { + e := n.dynamic.lru.Back() + e.mu.Lock() + + delete(n.cache, e.neigh.Addr) + n.dynamic.lru.Remove(e) + n.dynamic.count-- + + e.dispatchRemoveEventLocked() + e.setStateLocked(Unknown) + e.notifyWakersLocked() + e.mu.Unlock() + } + n.cache[remoteAddr] = entry + n.dynamic.lru.PushFront(entry) + n.dynamic.count++ + return entry +} + +// entry looks up the neighbor cache for translating address to link address +// (e.g. IP -> MAC). If the LinkEndpoint requests address resolution and there +// is a LinkAddressResolver registered with the network protocol, the cache +// attempts to resolve the address and returns ErrWouldBlock. If a Waker is +// provided, it will be notified when address resolution is complete (success +// or not). +// +// If address resolution is required, ErrNoLinkAddress and a notification +// channel is returned for the top level caller to block. Channel is closed +// once address resolution is complete (success or not). +func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkAddressResolver, w *sleep.Waker) (NeighborEntry, <-chan struct{}, *tcpip.Error) { + if linkRes != nil { + if linkAddr, ok := linkRes.ResolveStaticAddress(remoteAddr); ok { + e := NeighborEntry{ + Addr: remoteAddr, + LocalAddr: localAddr, + LinkAddr: linkAddr, + State: Static, + UpdatedAt: time.Now(), + } + return e, nil, nil + } + } + + entry := n.getOrCreateEntry(remoteAddr, localAddr, linkRes) + entry.mu.Lock() + defer entry.mu.Unlock() + + switch s := entry.neigh.State; s { + case Reachable, Static: + return entry.neigh, nil, nil + + case Unknown, Incomplete, Stale, Delay, Probe: + entry.addWakerLocked(w) + + if entry.done == nil { + // Address resolution needs to be initiated. + if linkRes == nil { + return entry.neigh, nil, tcpip.ErrNoLinkAddress + } + entry.done = make(chan struct{}) + } + + entry.handlePacketQueuedLocked() + return entry.neigh, entry.done, tcpip.ErrWouldBlock + + case Failed: + return entry.neigh, nil, tcpip.ErrNoLinkAddress + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", s)) + } +} + +// removeWaker removes a waker that has been added when link resolution for +// addr was requested. +func (n *neighborCache) removeWaker(addr tcpip.Address, waker *sleep.Waker) { + n.mu.Lock() + if entry, ok := n.cache[addr]; ok { + delete(entry.wakers, waker) + } + n.mu.Unlock() +} + +// entries returns all entries in the neighbor cache. +func (n *neighborCache) entries() []NeighborEntry { + entries := make([]NeighborEntry, 0, len(n.cache)) + n.mu.RLock() + for _, entry := range n.cache { + entry.mu.RLock() + entries = append(entries, entry.neigh) + entry.mu.RUnlock() + } + n.mu.RUnlock() + return entries +} + +// addStaticEntry adds a static entry to the neighbor cache, mapping an IP +// address to a link address. If a dynamic entry exists in the neighbor cache +// with the same address, it will be replaced with this static entry. If a +// static entry exists with the same address but different link address, it +// will be updated with the new link address. If a static entry exists with the +// same address and link address, nothing will happen. +func (n *neighborCache) addStaticEntry(addr tcpip.Address, linkAddr tcpip.LinkAddress) { + n.mu.Lock() + defer n.mu.Unlock() + + if entry, ok := n.cache[addr]; ok { + entry.mu.Lock() + if entry.neigh.State != Static { + // Dynamic entry found with the same address. + n.dynamic.lru.Remove(entry) + n.dynamic.count-- + } else if entry.neigh.LinkAddr == linkAddr { + // Static entry found with the same address and link address. + entry.mu.Unlock() + return + } else { + // Static entry found with the same address but different link address. + entry.neigh.LinkAddr = linkAddr + entry.dispatchChangeEventLocked(entry.neigh.State) + entry.mu.Unlock() + return + } + + // Notify that resolution has been interrupted, just in case the entry was + // in the Incomplete or Probe state. + entry.dispatchRemoveEventLocked() + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + entry.mu.Unlock() + } + + entry := newStaticNeighborEntry(n.nic, addr, linkAddr, n.state) + n.cache[addr] = entry +} + +// removeEntryLocked removes the specified entry from the neighbor cache. +func (n *neighborCache) removeEntryLocked(entry *neighborEntry) { + if entry.neigh.State != Static { + n.dynamic.lru.Remove(entry) + n.dynamic.count-- + } + if entry.neigh.State != Failed { + entry.dispatchRemoveEventLocked() + } + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + + delete(n.cache, entry.neigh.Addr) +} + +// removeEntry removes a dynamic or static entry by address from the neighbor +// cache. Returns true if the entry was found and deleted. +func (n *neighborCache) removeEntry(addr tcpip.Address) bool { + n.mu.Lock() + defer n.mu.Unlock() + + entry, ok := n.cache[addr] + if !ok { + return false + } + + entry.mu.Lock() + defer entry.mu.Unlock() + + n.removeEntryLocked(entry) + return true +} + +// clear removes all dynamic and static entries from the neighbor cache. +func (n *neighborCache) clear() { + n.mu.Lock() + defer n.mu.Unlock() + + for _, entry := range n.cache { + entry.mu.Lock() + entry.dispatchRemoveEventLocked() + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + entry.mu.Unlock() + } + + n.dynamic.lru = neighborEntryList{} + n.cache = make(map[tcpip.Address]*neighborEntry) + n.dynamic.count = 0 +} + +// config returns the NUD configuration. +func (n *neighborCache) config() NUDConfigurations { + return n.state.Config() +} + +// setConfig changes the NUD configuration. +// +// If config contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (n *neighborCache) setConfig(config NUDConfigurations) { + config.resetInvalidFields() + n.state.SetConfig(config) +} + +// HandleProbe implements NUDHandler.HandleProbe by following the logic defined +// in RFC 4861 section 7.2.3. Validation of the probe is expected to be handled +// by the caller. +func (n *neighborCache) HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress) { + entry := n.getOrCreateEntry(remoteAddr, localAddr, nil) + entry.mu.Lock() + entry.handleProbeLocked(remoteLinkAddr) + entry.mu.Unlock() +} + +// HandleConfirmation implements NUDHandler.HandleConfirmation by following the +// logic defined in RFC 4861 section 7.2.5. +// +// TODO(gvisor.dev/issue/2277): To protect against ARP poisoning and other +// attacks against NDP functions, Secure Neighbor Discovery (SEND) Protocol +// should be deployed where preventing access to the broadcast segment might +// not be possible. SEND uses RSA key pairs to produce cryptographically +// generated addresses, as defined in RFC 3972, Cryptographically Generated +// Addresses (CGA). This ensures that the claimed source of an NDP message is +// the owner of the claimed address. +func (n *neighborCache) HandleConfirmation(addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) { + n.mu.RLock() + entry, ok := n.cache[addr] + n.mu.RUnlock() + if ok { + entry.mu.Lock() + entry.handleConfirmationLocked(linkAddr, flags) + entry.mu.Unlock() + } + // The confirmation SHOULD be silently discarded if the recipient did not + // initiate any communication with the target. This is indicated if there is + // no matching entry for the remote address. +} + +// HandleUpperLevelConfirmation implements +// NUDHandler.HandleUpperLevelConfirmation by following the logic defined in +// RFC 4861 section 7.3.1. +func (n *neighborCache) HandleUpperLevelConfirmation(addr tcpip.Address) { + n.mu.RLock() + entry, ok := n.cache[addr] + n.mu.RUnlock() + if ok { + entry.mu.Lock() + entry.handleUpperLevelConfirmationLocked() + entry.mu.Unlock() + } +} diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go new file mode 100644 index 000000000..0068cacb8 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_entry.go @@ -0,0 +1,482 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "fmt" + "sync" + "time" + + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/tcpip" +) + +// NeighborEntry describes a neighboring device in the local network. +type NeighborEntry struct { + Addr tcpip.Address + LocalAddr tcpip.Address + LinkAddr tcpip.LinkAddress + State NeighborState + UpdatedAt time.Time +} + +// NeighborState defines the state of a NeighborEntry within the Neighbor +// Unreachability Detection state machine, as per RFC 4861 section 7.3.2. +type NeighborState uint8 + +const ( + // Unknown means reachability has not been verified yet. This is the initial + // state of entries that have been created automatically by the Neighbor + // Unreachability Detection state machine. + Unknown NeighborState = iota + // Incomplete means that there is an outstanding request to resolve the + // address. + Incomplete + // Reachable means the path to the neighbor is functioning properly for both + // receive and transmit paths. + Reachable + // Stale means reachability to the neighbor is unknown, but packets are still + // able to be transmitted to the possibly stale link address. + Stale + // Delay means reachability to the neighbor is unknown and pending + // confirmation from an upper-level protocol like TCP, but packets are still + // able to be transmitted to the possibly stale link address. + Delay + // Probe means a reachability confirmation is actively being sought by + // periodically retransmitting reachability probes until a reachability + // confirmation is received, or until the max amount of probes has been sent. + Probe + // Static describes entries that have been explicitly added by the user. They + // do not expire and are not deleted until explicitly removed. + Static + // Failed means traffic should not be sent to this neighbor since attempts of + // reachability have returned inconclusive. + Failed +) + +// neighborEntry implements a neighbor entry's individual node behavior, as per +// RFC 4861 section 7.3.3. Neighbor Unreachability Detection operates in +// parallel with the sending of packets to a neighbor, necessitating the +// entry's lock to be acquired for all operations. +type neighborEntry struct { + neighborEntryEntry + + nic *NIC + protocol tcpip.NetworkProtocolNumber + + // linkRes provides the functionality to send reachability probes, used in + // Neighbor Unreachability Detection. + linkRes LinkAddressResolver + + // nudState points to the Neighbor Unreachability Detection configuration. + nudState *NUDState + + // mu protects the fields below. + mu sync.RWMutex + + neigh NeighborEntry + + // wakers is a set of waiters for address resolution result. Anytime state + // transitions out of incomplete these waiters are notified. It is nil iff + // address resolution is ongoing and no clients are waiting for the result. + wakers map[*sleep.Waker]struct{} + + // done is used to allow callers to wait on address resolution. It is nil + // iff nudState is not Reachable and address resolution is not yet in + // progress. + done chan struct{} + + isRouter bool + job *tcpip.Job +} + +// newNeighborEntry creates a neighbor cache entry starting at the default +// state, Unknown. Transition out of Unknown by calling either +// `handlePacketQueuedLocked` or `handleProbeLocked` on the newly created +// neighborEntry. +func newNeighborEntry(nic *NIC, remoteAddr tcpip.Address, localAddr tcpip.Address, nudState *NUDState, linkRes LinkAddressResolver) *neighborEntry { + return &neighborEntry{ + nic: nic, + linkRes: linkRes, + nudState: nudState, + neigh: NeighborEntry{ + Addr: remoteAddr, + LocalAddr: localAddr, + State: Unknown, + }, + } +} + +// newStaticNeighborEntry creates a neighbor cache entry starting at the Static +// state. The entry can only transition out of Static by directly calling +// `setStateLocked`. +func newStaticNeighborEntry(nic *NIC, addr tcpip.Address, linkAddr tcpip.LinkAddress, state *NUDState) *neighborEntry { + if nic.stack.nudDisp != nil { + nic.stack.nudDisp.OnNeighborAdded(nic.id, addr, linkAddr, Static, time.Now()) + } + return &neighborEntry{ + nic: nic, + nudState: state, + neigh: NeighborEntry{ + Addr: addr, + LinkAddr: linkAddr, + State: Static, + UpdatedAt: time.Now(), + }, + } +} + +// addWaker adds w to the list of wakers waiting for address resolution. +// Assumes the entry has already been appropriately locked. +func (e *neighborEntry) addWakerLocked(w *sleep.Waker) { + if w == nil { + return + } + if e.wakers == nil { + e.wakers = make(map[*sleep.Waker]struct{}) + } + e.wakers[w] = struct{}{} +} + +// notifyWakersLocked notifies those waiting for address resolution, whether it +// succeeded or failed. Assumes the entry has already been appropriately locked. +func (e *neighborEntry) notifyWakersLocked() { + for w := range e.wakers { + w.Assert() + } + e.wakers = nil + if ch := e.done; ch != nil { + close(ch) + e.done = nil + } +} + +// dispatchAddEventLocked signals to stack's NUD Dispatcher that the entry has +// been added. +func (e *neighborEntry) dispatchAddEventLocked(nextState NeighborState) { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborAdded(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, nextState, time.Now()) + } +} + +// dispatchChangeEventLocked signals to stack's NUD Dispatcher that the entry +// has changed state or link-layer address. +func (e *neighborEntry) dispatchChangeEventLocked(nextState NeighborState) { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborChanged(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, nextState, time.Now()) + } +} + +// dispatchRemoveEventLocked signals to stack's NUD Dispatcher that the entry +// has been removed. +func (e *neighborEntry) dispatchRemoveEventLocked() { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborRemoved(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, e.neigh.State, time.Now()) + } +} + +// setStateLocked transitions the entry to the specified state immediately. +// +// Follows the logic defined in RFC 4861 section 7.3.3. +// +// e.mu MUST be locked. +func (e *neighborEntry) setStateLocked(next NeighborState) { + // Cancel the previously scheduled action, if there is one. Entries in + // Unknown, Stale, or Static state do not have scheduled actions. + if timer := e.job; timer != nil { + timer.Cancel() + } + + prev := e.neigh.State + e.neigh.State = next + e.neigh.UpdatedAt = time.Now() + config := e.nudState.Config() + + switch next { + case Incomplete: + var retryCounter uint32 + var sendMulticastProbe func() + + sendMulticastProbe = func() { + if retryCounter == config.MaxMulticastProbes { + // "If no Neighbor Advertisement is received after + // MAX_MULTICAST_SOLICIT solicitations, address resolution has failed. + // The sender MUST return ICMP destination unreachable indications with + // code 3 (Address Unreachable) for each packet queued awaiting address + // resolution." - RFC 4861 section 7.2.2 + // + // There is no need to send an ICMP destination unreachable indication + // since the failure to resolve the address is expected to only occur + // on this node. Thus, redirecting traffic is currently not supported. + // + // "If the error occurs on a node other than the node originating the + // packet, an ICMP error message is generated. If the error occurs on + // the originating node, an implementation is not required to actually + // create and send an ICMP error packet to the source, as long as the + // upper-layer sender is notified through an appropriate mechanism + // (e.g. return value from a procedure call). Note, however, that an + // implementation may find it convenient in some cases to return errors + // to the sender by taking the offending packet, generating an ICMP + // error message, and then delivering it (locally) through the generic + // error-handling routines.' - RFC 4861 section 2.1 + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, "", e.nic.linkEP); err != nil { + // There is no need to log the error here; the NUD implementation may + // assume a working link. A valid link should be the responsibility of + // the NIC/stack.LinkEndpoint. + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + retryCounter++ + e.job = e.nic.stack.newJob(&e.mu, sendMulticastProbe) + e.job.Schedule(config.RetransmitTimer) + } + + sendMulticastProbe() + + case Reachable: + e.job = e.nic.stack.newJob(&e.mu, func() { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + }) + e.job.Schedule(e.nudState.ReachableTime()) + + case Delay: + e.job = e.nic.stack.newJob(&e.mu, func() { + e.dispatchChangeEventLocked(Probe) + e.setStateLocked(Probe) + }) + e.job.Schedule(config.DelayFirstProbeTime) + + case Probe: + var retryCounter uint32 + var sendUnicastProbe func() + + sendUnicastProbe = func() { + if retryCounter == config.MaxUnicastProbes { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, e.neigh.LinkAddr, e.nic.linkEP); err != nil { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + retryCounter++ + if retryCounter == config.MaxUnicastProbes { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + e.job = e.nic.stack.newJob(&e.mu, sendUnicastProbe) + e.job.Schedule(config.RetransmitTimer) + } + + sendUnicastProbe() + + case Failed: + e.notifyWakersLocked() + e.job = e.nic.stack.newJob(&e.mu, func() { + e.nic.neigh.removeEntryLocked(e) + }) + e.job.Schedule(config.UnreachableTime) + + case Unknown, Stale, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid state transition from %q to %q", prev, next)) + } +} + +// handlePacketQueuedLocked advances the state machine according to a packet +// being queued for outgoing transmission. +// +// Follows the logic defined in RFC 4861 section 7.3.3. +func (e *neighborEntry) handlePacketQueuedLocked() { + switch e.neigh.State { + case Unknown: + e.dispatchAddEventLocked(Incomplete) + e.setStateLocked(Incomplete) + + case Stale: + e.dispatchChangeEventLocked(Delay) + e.setStateLocked(Delay) + + case Incomplete, Reachable, Delay, Probe, Static, Failed: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleProbeLocked processes an incoming neighbor probe (e.g. ARP request or +// Neighbor Solicitation for ARP or NDP, respectively). +// +// Follows the logic defined in RFC 4861 section 7.2.3. +func (e *neighborEntry) handleProbeLocked(remoteLinkAddr tcpip.LinkAddress) { + // Probes MUST be silently discarded if the target address is tentative, does + // not exist, or not bound to the NIC as per RFC 4861 section 7.2.3. These + // checks MUST be done by the NetworkEndpoint. + + switch e.neigh.State { + case Unknown, Incomplete, Failed: + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchAddEventLocked(Stale) + e.setStateLocked(Stale) + e.notifyWakersLocked() + + case Reachable, Delay, Probe: + if e.neigh.LinkAddr != remoteLinkAddr { + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + + case Stale: + if e.neigh.LinkAddr != remoteLinkAddr { + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchChangeEventLocked(Stale) + } + + case Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleConfirmationLocked processes an incoming neighbor confirmation +// (e.g. ARP reply or Neighbor Advertisement for ARP or NDP, respectively). +// +// Follows the state machine defined by RFC 4861 section 7.2.5. +// +// TODO(gvisor.dev/issue/2277): To protect against ARP poisoning and other +// attacks against NDP functions, Secure Neighbor Discovery (SEND) Protocol +// should be deployed where preventing access to the broadcast segment might +// not be possible. SEND uses RSA key pairs to produce Cryptographically +// Generated Addresses (CGA), as defined in RFC 3972. This ensures that the +// claimed source of an NDP message is the owner of the claimed address. +func (e *neighborEntry) handleConfirmationLocked(linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) { + switch e.neigh.State { + case Incomplete: + if len(linkAddr) == 0 { + // "If the link layer has addresses and no Target Link-Layer Address + // option is included, the receiving node SHOULD silently discard the + // received advertisement." - RFC 4861 section 7.2.5 + break + } + + e.neigh.LinkAddr = linkAddr + if flags.Solicited { + e.dispatchChangeEventLocked(Reachable) + e.setStateLocked(Reachable) + } else { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + e.isRouter = flags.IsRouter + e.notifyWakersLocked() + + // "Note that the Override flag is ignored if the entry is in the + // INCOMPLETE state." - RFC 4861 section 7.2.5 + + case Reachable, Stale, Delay, Probe: + sameLinkAddr := e.neigh.LinkAddr == linkAddr + + if !sameLinkAddr { + if !flags.Override { + if e.neigh.State == Reachable { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + break + } + + e.neigh.LinkAddr = linkAddr + + if !flags.Solicited { + if e.neigh.State != Stale { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } else { + // Notify the LinkAddr change, even though NUD state hasn't changed. + e.dispatchChangeEventLocked(e.neigh.State) + } + break + } + } + + if flags.Solicited && (flags.Override || sameLinkAddr) { + if e.neigh.State != Reachable { + e.dispatchChangeEventLocked(Reachable) + } + // Set state to Reachable again to refresh timers. + e.setStateLocked(Reachable) + e.notifyWakersLocked() + } + + if e.isRouter && !flags.IsRouter { + // "In those cases where the IsRouter flag changes from TRUE to FALSE as + // a result of this update, the node MUST remove that router from the + // Default Router List and update the Destination Cache entries for all + // destinations using that neighbor as a router as specified in Section + // 7.3.3. This is needed to detect when a node that is used as a router + // stops forwarding packets due to being configured as a host." + // - RFC 4861 section 7.2.5 + e.nic.mu.Lock() + e.nic.mu.ndp.invalidateDefaultRouter(e.neigh.Addr) + e.nic.mu.Unlock() + } + e.isRouter = flags.IsRouter + + case Unknown, Failed, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleUpperLevelConfirmationLocked processes an incoming upper-level protocol +// (e.g. TCP acknowledgements) reachability confirmation. +func (e *neighborEntry) handleUpperLevelConfirmationLocked() { + switch e.neigh.State { + case Reachable, Stale, Delay, Probe: + if e.neigh.State != Reachable { + e.dispatchChangeEventLocked(Reachable) + // Set state to Reachable again to refresh timers. + } + e.setStateLocked(Reachable) + + case Unknown, Incomplete, Failed, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} diff --git a/pkg/tcpip/stack/neighbor_entry_list.go b/pkg/tcpip/stack/neighbor_entry_list.go new file mode 100644 index 000000000..b732257d2 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_entry_list.go @@ -0,0 +1,193 @@ +package stack + +// ElementMapper provides an identity mapping by default. +// +// This can be replaced to provide a struct that maps elements to linker +// objects, if they are not the same. An ElementMapper is not typically +// required if: Linker is left as is, Element is left as is, or Linker and +// Element are the same type. +type neighborEntryElementMapper struct{} + +// linkerFor maps an Element to a Linker. +// +// This default implementation should be inlined. +// +//go:nosplit +func (neighborEntryElementMapper) linkerFor(elem *neighborEntry) *neighborEntry { return elem } + +// List is an intrusive list. Entries can be added to or removed from the list +// in O(1) time and with no additional memory allocations. +// +// The zero value for List is an empty list ready to use. +// +// To iterate over a list (where l is a List): +// for e := l.Front(); e != nil; e = e.Next() { +// // do something with e. +// } +// +// +stateify savable +type neighborEntryList struct { + head *neighborEntry + tail *neighborEntry +} + +// Reset resets list l to the empty state. +func (l *neighborEntryList) Reset() { + l.head = nil + l.tail = nil +} + +// Empty returns true iff the list is empty. +func (l *neighborEntryList) Empty() bool { + return l.head == nil +} + +// Front returns the first element of list l or nil. +func (l *neighborEntryList) Front() *neighborEntry { + return l.head +} + +// Back returns the last element of list l or nil. +func (l *neighborEntryList) Back() *neighborEntry { + return l.tail +} + +// Len returns the number of elements in the list. +// +// NOTE: This is an O(n) operation. +func (l *neighborEntryList) Len() (count int) { + for e := l.Front(); e != nil; e = (neighborEntryElementMapper{}.linkerFor(e)).Next() { + count++ + } + return count +} + +// PushFront inserts the element e at the front of list l. +func (l *neighborEntryList) PushFront(e *neighborEntry) { + linker := neighborEntryElementMapper{}.linkerFor(e) + linker.SetNext(l.head) + linker.SetPrev(nil) + if l.head != nil { + neighborEntryElementMapper{}.linkerFor(l.head).SetPrev(e) + } else { + l.tail = e + } + + l.head = e +} + +// PushBack inserts the element e at the back of list l. +func (l *neighborEntryList) PushBack(e *neighborEntry) { + linker := neighborEntryElementMapper{}.linkerFor(e) + linker.SetNext(nil) + linker.SetPrev(l.tail) + if l.tail != nil { + neighborEntryElementMapper{}.linkerFor(l.tail).SetNext(e) + } else { + l.head = e + } + + l.tail = e +} + +// PushBackList inserts list m at the end of list l, emptying m. +func (l *neighborEntryList) PushBackList(m *neighborEntryList) { + if l.head == nil { + l.head = m.head + l.tail = m.tail + } else if m.head != nil { + neighborEntryElementMapper{}.linkerFor(l.tail).SetNext(m.head) + neighborEntryElementMapper{}.linkerFor(m.head).SetPrev(l.tail) + + l.tail = m.tail + } + m.head = nil + m.tail = nil +} + +// InsertAfter inserts e after b. +func (l *neighborEntryList) InsertAfter(b, e *neighborEntry) { + bLinker := neighborEntryElementMapper{}.linkerFor(b) + eLinker := neighborEntryElementMapper{}.linkerFor(e) + + a := bLinker.Next() + + eLinker.SetNext(a) + eLinker.SetPrev(b) + bLinker.SetNext(e) + + if a != nil { + neighborEntryElementMapper{}.linkerFor(a).SetPrev(e) + } else { + l.tail = e + } +} + +// InsertBefore inserts e before a. +func (l *neighborEntryList) InsertBefore(a, e *neighborEntry) { + aLinker := neighborEntryElementMapper{}.linkerFor(a) + eLinker := neighborEntryElementMapper{}.linkerFor(e) + + b := aLinker.Prev() + eLinker.SetNext(a) + eLinker.SetPrev(b) + aLinker.SetPrev(e) + + if b != nil { + neighborEntryElementMapper{}.linkerFor(b).SetNext(e) + } else { + l.head = e + } +} + +// Remove removes e from l. +func (l *neighborEntryList) Remove(e *neighborEntry) { + linker := neighborEntryElementMapper{}.linkerFor(e) + prev := linker.Prev() + next := linker.Next() + + if prev != nil { + neighborEntryElementMapper{}.linkerFor(prev).SetNext(next) + } else if l.head == e { + l.head = next + } + + if next != nil { + neighborEntryElementMapper{}.linkerFor(next).SetPrev(prev) + } else if l.tail == e { + l.tail = prev + } + + linker.SetNext(nil) + linker.SetPrev(nil) +} + +// Entry is a default implementation of Linker. Users can add anonymous fields +// of this type to their structs to make them automatically implement the +// methods needed by List. +// +// +stateify savable +type neighborEntryEntry struct { + next *neighborEntry + prev *neighborEntry +} + +// Next returns the entry that follows e in the list. +func (e *neighborEntryEntry) Next() *neighborEntry { + return e.next +} + +// Prev returns the entry that precedes e in the list. +func (e *neighborEntryEntry) Prev() *neighborEntry { + return e.prev +} + +// SetNext assigns 'entry' as the entry that follows e in the list. +func (e *neighborEntryEntry) SetNext(elem *neighborEntry) { + e.next = elem +} + +// SetPrev assigns 'entry' as the entry that precedes e in the list. +func (e *neighborEntryEntry) SetPrev(elem *neighborEntry) { + e.prev = elem +} diff --git a/pkg/tcpip/stack/neighborstate_string.go b/pkg/tcpip/stack/neighborstate_string.go new file mode 100644 index 000000000..aa7311ec6 --- /dev/null +++ b/pkg/tcpip/stack/neighborstate_string.go @@ -0,0 +1,44 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Code generated by "stringer -type NeighborState"; DO NOT EDIT. + +package stack + +import "strconv" + +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[Unknown-0] + _ = x[Incomplete-1] + _ = x[Reachable-2] + _ = x[Stale-3] + _ = x[Delay-4] + _ = x[Probe-5] + _ = x[Static-6] + _ = x[Failed-7] +} + +const _NeighborState_name = "UnknownIncompleteReachableStaleDelayProbeStaticFailed" + +var _NeighborState_index = [...]uint8{0, 7, 17, 26, 31, 36, 41, 47, 53} + +func (i NeighborState) String() string { + if i >= NeighborState(len(_NeighborState_index)-1) { + return "NeighborState(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _NeighborState_name[_NeighborState_index[i]:_NeighborState_index[i+1]] +} diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index fea0ce7e8..f21066fce 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -16,6 +16,7 @@ package stack import ( "fmt" + "math/rand" "reflect" "sort" "strings" @@ -45,6 +46,7 @@ type NIC struct { context NICContext stats NICStats + neigh *neighborCache mu struct { sync.RWMutex @@ -141,6 +143,16 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC nic.mu.packetEPs[netProto.Number()] = []PacketEndpoint{} } + // Check for Neighbor Unreachability Detection support. + if ep.Capabilities()&CapabilityResolutionRequired != 0 && len(stack.linkAddrResolvers) != 0 { + rng := rand.New(rand.NewSource(stack.clock.NowNanoseconds())) + nic.neigh = &neighborCache{ + nic: nic, + state: NewNUDState(stack.nudConfigs, rng), + cache: make(map[tcpip.Address]*neighborEntry, neighborCacheSize), + } + } + nic.linkEP.Attach(nic) return nic @@ -181,7 +193,7 @@ func (n *NIC) disableLocked() *tcpip.Error { return nil } - // TODO(b/147015577): Should Routes that are currently bound to n be + // TODO(gvisor.dev/issue/1491): Should Routes that are currently bound to n be // invalidated? Currently, Routes will continue to work when a NIC is enabled // again, and applications may not know that the underlying NIC was ever // disabled. @@ -1540,6 +1552,27 @@ func (n *NIC) setNDPConfigs(c NDPConfigurations) { n.mu.Unlock() } +// NUDConfigs gets the NUD configurations for n. +func (n *NIC) NUDConfigs() (NUDConfigurations, *tcpip.Error) { + if n.neigh == nil { + return NUDConfigurations{}, tcpip.ErrNotSupported + } + return n.neigh.config(), nil +} + +// setNUDConfigs sets the NUD configurations for n. +// +// Note, if c contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (n *NIC) setNUDConfigs(c NUDConfigurations) *tcpip.Error { + if n.neigh == nil { + return tcpip.ErrNotSupported + } + c.resetInvalidFields() + n.neigh.setConfig(c) + return nil +} + // handleNDPRA handles an NDP Router Advertisement message that arrived on n. func (n *NIC) handleNDPRA(ip tcpip.Address, ra header.NDPRouterAdvert) { n.mu.Lock() diff --git a/pkg/tcpip/stack/nud.go b/pkg/tcpip/stack/nud.go new file mode 100644 index 000000000..f848d50ad --- /dev/null +++ b/pkg/tcpip/stack/nud.go @@ -0,0 +1,466 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "math" + "sync" + "time" + + "gvisor.dev/gvisor/pkg/tcpip" +) + +const ( + // defaultBaseReachableTime is the default base duration for computing the + // random reachable time. + // + // Reachable time is the duration for which a neighbor is considered + // reachable after a positive reachability confirmation is received. It is a + // function of a uniformly distributed random value between the minimum and + // maximum random factors, multiplied by the base reachable time. Using a + // random component eliminates the possibility that Neighbor Unreachability + // Detection messages will synchronize with each other. + // + // Default taken from REACHABLE_TIME of RFC 4861 section 10. + defaultBaseReachableTime = 30 * time.Second + + // minimumBaseReachableTime is the minimum base duration for computing the + // random reachable time. + // + // Minimum = 1ms + minimumBaseReachableTime = time.Millisecond + + // defaultMinRandomFactor is the default minimum value of the random factor + // used for computing reachable time. + // + // Default taken from MIN_RANDOM_FACTOR of RFC 4861 section 10. + defaultMinRandomFactor = 0.5 + + // defaultMaxRandomFactor is the default maximum value of the random factor + // used for computing reachable time. + // + // The default value depends on the value of MinRandomFactor. + // If MinRandomFactor is less than MAX_RANDOM_FACTOR of RFC 4861 section 10, + // the value from the RFC will be used; otherwise, the default is + // MinRandomFactor multiplied by three. + defaultMaxRandomFactor = 1.5 + + // defaultRetransmitTimer is the default amount of time to wait between + // sending reachability probes. + // + // Default taken from RETRANS_TIMER of RFC 4861 section 10. + defaultRetransmitTimer = time.Second + + // minimumRetransmitTimer is the minimum amount of time to wait between + // sending reachability probes. + // + // Note, RFC 4861 does not impose a minimum Retransmit Timer, but we do here + // to make sure the messages are not sent all at once. We also come to this + // value because in the RetransmitTimer field of a Router Advertisement, a + // value of 0 means unspecified, so the smallest valid value is 1. Note, the + // unit of the RetransmitTimer field in the Router Advertisement is + // milliseconds. + minimumRetransmitTimer = time.Millisecond + + // defaultDelayFirstProbeTime is the default duration to wait for a + // non-Neighbor-Discovery related protocol to reconfirm reachability after + // entering the DELAY state. After this time, a reachability probe will be + // sent and the entry will transition to the PROBE state. + // + // Default taken from DELAY_FIRST_PROBE_TIME of RFC 4861 section 10. + defaultDelayFirstProbeTime = 5 * time.Second + + // defaultMaxMulticastProbes is the default number of reachabililty probes + // to send before concluding negative reachability and deleting the neighbor + // entry from the INCOMPLETE state. + // + // Default taken from MAX_MULTICAST_SOLICIT of RFC 4861 section 10. + defaultMaxMulticastProbes = 3 + + // defaultMaxUnicastProbes is the default number of reachability probes to + // send before concluding retransmission from within the PROBE state should + // cease and the entry SHOULD be deleted. + // + // Default taken from MAX_UNICASE_SOLICIT of RFC 4861 section 10. + defaultMaxUnicastProbes = 3 + + // defaultMaxAnycastDelayTime is the default time in which the stack SHOULD + // delay sending a response for a random time between 0 and this time, if the + // target address is an anycast address. + // + // Default taken from MAX_ANYCAST_DELAY_TIME of RFC 4861 section 10. + defaultMaxAnycastDelayTime = time.Second + + // defaultMaxReachbilityConfirmations is the default amount of unsolicited + // reachability confirmation messages a node MAY send to all-node multicast + // address when it determines its link-layer address has changed. + // + // Default taken from MAX_NEIGHBOR_ADVERTISEMENT of RFC 4861 section 10. + defaultMaxReachbilityConfirmations = 3 + + // defaultUnreachableTime is the default duration for how long an entry will + // remain in the FAILED state before being removed from the neighbor cache. + // + // Note, there is no equivalent protocol constant defined in RFC 4861. It + // leaves the specifics of any garbage collection mechanism up to the + // implementation. + defaultUnreachableTime = 5 * time.Second +) + +// NUDDispatcher is the interface integrators of netstack must implement to +// receive and handle NUD related events. +type NUDDispatcher interface { + // OnNeighborAdded will be called when a new entry is added to a NIC's (with + // ID nicID) neighbor table. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborAdded(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) + + // OnNeighborChanged will be called when an entry in a NIC's (with ID nicID) + // neighbor table changes state and/or link address. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborChanged(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) + + // OnNeighborRemoved will be called when an entry is removed from a NIC's + // (with ID nicID) neighbor table. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborRemoved(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) +} + +// ReachabilityConfirmationFlags describes the flags used within a reachability +// confirmation (e.g. ARP reply or Neighbor Advertisement for ARP or NDP, +// respectively). +type ReachabilityConfirmationFlags struct { + // Solicited indicates that the advertisement was sent in response to a + // reachability probe. + Solicited bool + + // Override indicates that the reachability confirmation should override an + // existing neighbor cache entry and update the cached link-layer address. + // When Override is not set the confirmation will not update a cached + // link-layer address, but will update an existing neighbor cache entry for + // which no link-layer address is known. + Override bool + + // IsRouter indicates that the sender is a router. + IsRouter bool +} + +// NUDHandler communicates external events to the Neighbor Unreachability +// Detection state machine, which is implemented per-interface. This is used by +// network endpoints to inform the Neighbor Cache of probes and confirmations. +type NUDHandler interface { + // HandleProbe processes an incoming neighbor probe (e.g. ARP request or + // Neighbor Solicitation for ARP or NDP, respectively). Validation of the + // probe needs to be performed before calling this function since the + // Neighbor Cache doesn't have access to view the NIC's assigned addresses. + HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress) + + // HandleConfirmation processes an incoming neighbor confirmation (e.g. ARP + // reply or Neighbor Advertisement for ARP or NDP, respectively). + HandleConfirmation(addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) + + // HandleUpperLevelConfirmation processes an incoming upper-level protocol + // (e.g. TCP acknowledgements) reachability confirmation. + HandleUpperLevelConfirmation(addr tcpip.Address) +} + +// NUDConfigurations is the NUD configurations for the netstack. This is used +// by the neighbor cache to operate the NUD state machine on each device in the +// local network. +type NUDConfigurations struct { + // BaseReachableTime is the base duration for computing the random reachable + // time. + // + // Reachable time is the duration for which a neighbor is considered + // reachable after a positive reachability confirmation is received. It is a + // function of uniformly distributed random value between minRandomFactor and + // maxRandomFactor multiplied by baseReachableTime. Using a random component + // eliminates the possibility that Neighbor Unreachability Detection messages + // will synchronize with each other. + // + // After this time, a neighbor entry will transition from REACHABLE to STALE + // state. + // + // Must be greater than 0. + BaseReachableTime time.Duration + + // LearnBaseReachableTime enables learning BaseReachableTime during runtime + // from the neighbor discovery protocol, if supported. + // + // TODO(gvisor.dev/issue/2240): Implement this NUD configuration option. + LearnBaseReachableTime bool + + // MinRandomFactor is the minimum value of the random factor used for + // computing reachable time. + // + // See BaseReachbleTime for more information on computing the reachable time. + // + // Must be greater than 0. + MinRandomFactor float32 + + // MaxRandomFactor is the maximum value of the random factor used for + // computing reachabile time. + // + // See BaseReachbleTime for more information on computing the reachable time. + // + // Must be great than or equal to MinRandomFactor. + MaxRandomFactor float32 + + // RetransmitTimer is the duration between retransmission of reachability + // probes in the PROBE state. + RetransmitTimer time.Duration + + // LearnRetransmitTimer enables learning RetransmitTimer during runtime from + // the neighbor discovery protocol, if supported. + // + // TODO(gvisor.dev/issue/2241): Implement this NUD configuration option. + LearnRetransmitTimer bool + + // DelayFirstProbeTime is the duration to wait for a non-Neighbor-Discovery + // related protocol to reconfirm reachability after entering the DELAY state. + // After this time, a reachability probe will be sent and the entry will + // transition to the PROBE state. + // + // Must be greater than 0. + DelayFirstProbeTime time.Duration + + // MaxMulticastProbes is the number of reachability probes to send before + // concluding negative reachability and deleting the neighbor entry from the + // INCOMPLETE state. + // + // Must be greater than 0. + MaxMulticastProbes uint32 + + // MaxUnicastProbes is the number of reachability probes to send before + // concluding retransmission from within the PROBE state should cease and + // entry SHOULD be deleted. + // + // Must be greater than 0. + MaxUnicastProbes uint32 + + // MaxAnycastDelayTime is the time in which the stack SHOULD delay sending a + // response for a random time between 0 and this time, if the target address + // is an anycast address. + // + // TODO(gvisor.dev/issue/2242): Use this option when sending solicited + // neighbor confirmations to anycast addresses and proxying neighbor + // confirmations. + MaxAnycastDelayTime time.Duration + + // MaxReachabilityConfirmations is the number of unsolicited reachability + // confirmation messages a node MAY send to all-node multicast address when + // it determines its link-layer address has changed. + // + // TODO(gvisor.dev/issue/2246): Discuss if implementation of this NUD + // configuration option is necessary. + MaxReachabilityConfirmations uint32 + + // UnreachableTime describes how long an entry will remain in the FAILED + // state before being removed from the neighbor cache. + UnreachableTime time.Duration +} + +// DefaultNUDConfigurations returns a NUDConfigurations populated with default +// values defined by RFC 4861 section 10. +func DefaultNUDConfigurations() NUDConfigurations { + return NUDConfigurations{ + BaseReachableTime: defaultBaseReachableTime, + LearnBaseReachableTime: true, + MinRandomFactor: defaultMinRandomFactor, + MaxRandomFactor: defaultMaxRandomFactor, + RetransmitTimer: defaultRetransmitTimer, + LearnRetransmitTimer: true, + DelayFirstProbeTime: defaultDelayFirstProbeTime, + MaxMulticastProbes: defaultMaxMulticastProbes, + MaxUnicastProbes: defaultMaxUnicastProbes, + MaxAnycastDelayTime: defaultMaxAnycastDelayTime, + MaxReachabilityConfirmations: defaultMaxReachbilityConfirmations, + UnreachableTime: defaultUnreachableTime, + } +} + +// resetInvalidFields modifies an invalid NDPConfigurations with valid values. +// If invalid values are present in c, the corresponding default values will be +// used instead. This is needed to check, and conditionally fix, user-specified +// NUDConfigurations. +func (c *NUDConfigurations) resetInvalidFields() { + if c.BaseReachableTime < minimumBaseReachableTime { + c.BaseReachableTime = defaultBaseReachableTime + } + if c.MinRandomFactor <= 0 { + c.MinRandomFactor = defaultMinRandomFactor + } + if c.MaxRandomFactor < c.MinRandomFactor { + c.MaxRandomFactor = calcMaxRandomFactor(c.MinRandomFactor) + } + if c.RetransmitTimer < minimumRetransmitTimer { + c.RetransmitTimer = defaultRetransmitTimer + } + if c.DelayFirstProbeTime == 0 { + c.DelayFirstProbeTime = defaultDelayFirstProbeTime + } + if c.MaxMulticastProbes == 0 { + c.MaxMulticastProbes = defaultMaxMulticastProbes + } + if c.MaxUnicastProbes == 0 { + c.MaxUnicastProbes = defaultMaxUnicastProbes + } + if c.UnreachableTime == 0 { + c.UnreachableTime = defaultUnreachableTime + } +} + +// calcMaxRandomFactor calculates the maximum value of the random factor used +// for computing reachable time. This function is necessary for when the +// default specified in RFC 4861 section 10 is less than the current +// MinRandomFactor. +// +// Assumes minRandomFactor is positive since validation of the minimum value +// should come before the validation of the maximum. +func calcMaxRandomFactor(minRandomFactor float32) float32 { + if minRandomFactor > defaultMaxRandomFactor { + return minRandomFactor * 3 + } + return defaultMaxRandomFactor +} + +// A Rand is a source of random numbers. +type Rand interface { + // Float32 returns, as a float32, a pseudo-random number in [0.0,1.0). + Float32() float32 +} + +// NUDState stores states needed for calculating reachable time. +type NUDState struct { + rng Rand + + // mu protects the fields below. + // + // It is necessary for NUDState to handle its own locking since neighbor + // entries may access the NUD state from within the goroutine spawned by + // time.AfterFunc(). This goroutine may run concurrently with the main + // process for controlling the neighbor cache and would otherwise introduce + // race conditions if NUDState was not locked properly. + mu sync.RWMutex + + config NUDConfigurations + + // reachableTime is the duration to wait for a REACHABLE entry to + // transition into STALE after inactivity. This value is calculated with + // the algorithm defined in RFC 4861 section 6.3.2. + reachableTime time.Duration + + expiration time.Time + prevBaseReachableTime time.Duration + prevMinRandomFactor float32 + prevMaxRandomFactor float32 +} + +// NewNUDState returns new NUDState using c as configuration and the specified +// random number generator for use in recomputing ReachableTime. +func NewNUDState(c NUDConfigurations, rng Rand) *NUDState { + s := &NUDState{ + rng: rng, + } + s.config = c + return s +} + +// Config returns the NUD configuration. +func (s *NUDState) Config() NUDConfigurations { + s.mu.RLock() + defer s.mu.RUnlock() + return s.config +} + +// SetConfig replaces the existing NUD configurations with c. +func (s *NUDState) SetConfig(c NUDConfigurations) { + s.mu.Lock() + defer s.mu.Unlock() + s.config = c +} + +// ReachableTime returns the duration to wait for a REACHABLE entry to +// transition into STALE after inactivity. This value is recalculated for new +// values of BaseReachableTime, MinRandomFactor, and MaxRandomFactor using the +// algorithm defined in RFC 4861 section 6.3.2. +func (s *NUDState) ReachableTime() time.Duration { + s.mu.Lock() + defer s.mu.Unlock() + + if time.Now().After(s.expiration) || + s.config.BaseReachableTime != s.prevBaseReachableTime || + s.config.MinRandomFactor != s.prevMinRandomFactor || + s.config.MaxRandomFactor != s.prevMaxRandomFactor { + return s.recomputeReachableTimeLocked() + } + return s.reachableTime +} + +// recomputeReachableTimeLocked forces a recalculation of ReachableTime using +// the algorithm defined in RFC 4861 section 6.3.2. +// +// This SHOULD automatically be invoked during certain situations, as per +// RFC 4861 section 6.3.4: +// +// If the received Reachable Time value is non-zero, the host SHOULD set its +// BaseReachableTime variable to the received value. If the new value +// differs from the previous value, the host SHOULD re-compute a new random +// ReachableTime value. ReachableTime is computed as a uniformly +// distributed random value between MIN_RANDOM_FACTOR and MAX_RANDOM_FACTOR +// times the BaseReachableTime. Using a random component eliminates the +// possibility that Neighbor Unreachability Detection messages will +// synchronize with each other. +// +// In most cases, the advertised Reachable Time value will be the same in +// consecutive Router Advertisements, and a host's BaseReachableTime rarely +// changes. In such cases, an implementation SHOULD ensure that a new +// random value gets re-computed at least once every few hours. +// +// s.mu MUST be locked for writing. +func (s *NUDState) recomputeReachableTimeLocked() time.Duration { + s.prevBaseReachableTime = s.config.BaseReachableTime + s.prevMinRandomFactor = s.config.MinRandomFactor + s.prevMaxRandomFactor = s.config.MaxRandomFactor + + randomFactor := s.config.MinRandomFactor + s.rng.Float32()*(s.config.MaxRandomFactor-s.config.MinRandomFactor) + + // Check for overflow, given that minRandomFactor and maxRandomFactor are + // guaranteed to be positive numbers. + if float32(math.MaxInt64)/randomFactor < float32(s.config.BaseReachableTime) { + s.reachableTime = time.Duration(math.MaxInt64) + } else if randomFactor == 1 { + // Avoid loss of precision when a large base reachable time is used. + s.reachableTime = s.config.BaseReachableTime + } else { + reachableTime := int64(float32(s.config.BaseReachableTime) * randomFactor) + s.reachableTime = time.Duration(reachableTime) + } + + s.expiration = time.Now().Add(2 * time.Hour) + return s.reachableTime +} diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go index d65f8049e..91e0110f1 100644 --- a/pkg/tcpip/stack/route.go +++ b/pkg/tcpip/stack/route.go @@ -48,6 +48,10 @@ type Route struct { // Loop controls where WritePacket should send packets. Loop PacketLooping + + // directedBroadcast indicates whether this route is sending a directed + // broadcast packet. + directedBroadcast bool } // makeRoute initializes a new route. It takes ownership of the provided @@ -275,6 +279,12 @@ func (r *Route) Stack() *Stack { return r.ref.stack() } +// IsBroadcast returns true if the route is to send a broadcast packet. +func (r *Route) IsBroadcast() bool { + // Only IPv4 has a notion of broadcast. + return r.directedBroadcast || r.RemoteAddress == header.IPv4Broadcast +} + // ReverseRoute returns new route with given source and destination address. func (r *Route) ReverseRoute(src tcpip.Address, dst tcpip.Address) Route { return Route{ diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index a6faa22c2..3f07e4159 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -445,6 +445,9 @@ type Stack struct { // ndpConfigs is the default NDP configurations used by interfaces. ndpConfigs NDPConfigurations + // nudConfigs is the default NUD configurations used by interfaces. + nudConfigs NUDConfigurations + // autoGenIPv6LinkLocal determines whether or not the stack will attempt // to auto-generate an IPv6 link-local address for newly enabled non-loopback // NICs. See the AutoGenIPv6LinkLocal field of Options for more details. @@ -454,6 +457,10 @@ type Stack struct { // integrator NDP related events. ndpDisp NDPDispatcher + // nudDisp is the NUD event dispatcher that is used to send the netstack + // integrator NUD related events. + nudDisp NUDDispatcher + // uniqueIDGenerator is a generator of unique identifiers. uniqueIDGenerator UniqueID @@ -518,6 +525,9 @@ type Options struct { // before assigning an address to a NIC. NDPConfigs NDPConfigurations + // NUDConfigs is the default NUD configurations used by interfaces. + NUDConfigs NUDConfigurations + // AutoGenIPv6LinkLocal determines whether or not the stack will attempt to // auto-generate an IPv6 link-local address for newly enabled non-loopback // NICs. @@ -536,6 +546,10 @@ type Options struct { // receive NDP related events. NDPDisp NDPDispatcher + // NUDDisp is the NUD event dispatcher that an integrator can provide to + // receive NUD related events. + NUDDisp NUDDispatcher + // RawFactory produces raw endpoints. Raw endpoints are enabled only if // this is non-nil. RawFactory RawFactory @@ -670,6 +684,8 @@ func New(opts Options) *Stack { // Make sure opts.NDPConfigs contains valid values only. opts.NDPConfigs.validate() + opts.NUDConfigs.resetInvalidFields() + s := &Stack{ transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), @@ -685,9 +701,11 @@ func New(opts Options) *Stack { icmpRateLimiter: NewICMPRateLimiter(), seed: generateRandUint32(), ndpConfigs: opts.NDPConfigs, + nudConfigs: opts.NUDConfigs, autoGenIPv6LinkLocal: opts.AutoGenIPv6LinkLocal, uniqueIDGenerator: opts.UniqueID, ndpDisp: opts.NDPDisp, + nudDisp: opts.NUDDisp, opaqueIIDOpts: opts.OpaqueIIDOpts, tempIIDSeed: opts.TempIIDSeed, forwarder: newForwardQueue(), @@ -1284,9 +1302,9 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n s.mu.RLock() defer s.mu.RUnlock() - isBroadcast := remoteAddr == header.IPv4Broadcast + isLocalBroadcast := remoteAddr == header.IPv4Broadcast isMulticast := header.IsV4MulticastAddress(remoteAddr) || header.IsV6MulticastAddress(remoteAddr) - needRoute := !(isBroadcast || isMulticast || header.IsV6LinkLocalAddress(remoteAddr)) + needRoute := !(isLocalBroadcast || isMulticast || header.IsV6LinkLocalAddress(remoteAddr)) if id != 0 && !needRoute { if nic, ok := s.nics[id]; ok && nic.enabled() { if ref := s.getRefEP(nic, localAddr, remoteAddr, netProto); ref != nil { @@ -1307,9 +1325,16 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n } r := makeRoute(netProto, ref.ep.ID().LocalAddress, remoteAddr, nic.linkEP.LinkAddress(), ref, s.handleLocal && !nic.isLoopback(), multicastLoop && !nic.isLoopback()) - if needRoute { - r.NextHop = route.Gateway + r.directedBroadcast = route.Destination.IsBroadcast(remoteAddr) + + if len(route.Gateway) > 0 { + if needRoute { + r.NextHop = route.Gateway + } + } else if r.directedBroadcast { + r.RemoteLinkAddress = header.EthernetBroadcastAddress } + return r, nil } } @@ -1862,10 +1887,38 @@ func (s *Stack) SetNDPConfigurations(id tcpip.NICID, c NDPConfigurations) *tcpip } nic.setNDPConfigs(c) - return nil } +// NUDConfigurations gets the per-interface NUD configurations. +func (s *Stack) NUDConfigurations(id tcpip.NICID) (NUDConfigurations, *tcpip.Error) { + s.mu.RLock() + nic, ok := s.nics[id] + s.mu.RUnlock() + + if !ok { + return NUDConfigurations{}, tcpip.ErrUnknownNICID + } + + return nic.NUDConfigs() +} + +// SetNUDConfigurations sets the per-interface NUD configurations. +// +// Note, if c contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (s *Stack) SetNUDConfigurations(id tcpip.NICID, c NUDConfigurations) *tcpip.Error { + s.mu.RLock() + nic, ok := s.nics[id] + s.mu.RUnlock() + + if !ok { + return tcpip.ErrUnknownNICID + } + + return nic.setNUDConfigs(c) +} + // HandleNDPRA provides a NIC with ID id a validated NDP Router Advertisement // message that it needs to handle. func (s *Stack) HandleNDPRA(id tcpip.NICID, ip tcpip.Address, ra header.NDPRouterAdvert) *tcpip.Error { diff --git a/pkg/tcpip/stack/stack_state_autogen.go b/pkg/tcpip/stack/stack_state_autogen.go index fbc67b2d5..44e7c6ff1 100644 --- a/pkg/tcpip/stack/stack_state_autogen.go +++ b/pkg/tcpip/stack/stack_state_autogen.go @@ -383,6 +383,58 @@ func (x *linkAddrEntryEntry) StateLoad(m state.Source) { m.Load(1, &x.prev) } +func (x *neighborEntryList) StateTypeName() string { + return "pkg/tcpip/stack.neighborEntryList" +} + +func (x *neighborEntryList) StateFields() []string { + return []string{ + "head", + "tail", + } +} + +func (x *neighborEntryList) beforeSave() {} + +func (x *neighborEntryList) StateSave(m state.Sink) { + x.beforeSave() + m.Save(0, &x.head) + m.Save(1, &x.tail) +} + +func (x *neighborEntryList) afterLoad() {} + +func (x *neighborEntryList) StateLoad(m state.Source) { + m.Load(0, &x.head) + m.Load(1, &x.tail) +} + +func (x *neighborEntryEntry) StateTypeName() string { + return "pkg/tcpip/stack.neighborEntryEntry" +} + +func (x *neighborEntryEntry) StateFields() []string { + return []string{ + "next", + "prev", + } +} + +func (x *neighborEntryEntry) beforeSave() {} + +func (x *neighborEntryEntry) StateSave(m state.Sink) { + x.beforeSave() + m.Save(0, &x.next) + m.Save(1, &x.prev) +} + +func (x *neighborEntryEntry) afterLoad() {} + +func (x *neighborEntryEntry) StateLoad(m state.Source) { + m.Load(0, &x.next) + m.Load(1, &x.prev) +} + func (x *PacketBufferList) StateTypeName() string { return "pkg/tcpip/stack.PacketBufferList" } @@ -651,6 +703,8 @@ func init() { state.Register((*IPHeaderFilter)(nil)) state.Register((*linkAddrEntryList)(nil)) state.Register((*linkAddrEntryEntry)(nil)) + state.Register((*neighborEntryList)(nil)) + state.Register((*neighborEntryEntry)(nil)) state.Register((*PacketBufferList)(nil)) state.Register((*PacketBufferEntry)(nil)) state.Register((*TransportEndpointID)(nil)) diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 21aafb0a2..45f59b60f 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -43,6 +43,9 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) +// Using header.IPv4AddressSize would cause an import cycle. +const ipv4AddressSize = 4 + // Error represents an error in the netstack error space. Using a special type // ensures that errors outside of this space are not accidentally introduced. // @@ -320,6 +323,29 @@ func (s *Subnet) Broadcast() Address { return Address(addr) } +// IsBroadcast returns true if the address is considered a broadcast address. +func (s *Subnet) IsBroadcast(address Address) bool { + // Only IPv4 supports the notion of a broadcast address. + if len(address) != ipv4AddressSize { + return false + } + + // Normally, we would just compare address with the subnet's broadcast + // address but there is an exception where a simple comparison is not + // correct. This exception is for /31 and /32 IPv4 subnets where all + // addresses are considered valid host addresses. + // + // For /31 subnets, the case is easy. RFC 3021 Section 2.1 states that + // both addresses in a /31 subnet "MUST be interpreted as host addresses." + // + // For /32, the case is a bit more vague. RFC 3021 makes no mention of /32 + // subnets. However, the same reasoning applies - if an exception is not + // made, then there do not exist any host addresses in a /32 subnet. RFC + // 4632 Section 3.1 also vaguely implies this interpretation by referring + // to addresses in /32 subnets as "host routes." + return s.Prefix() <= 30 && s.Broadcast() == address +} + // Equal returns true if s equals o. // // Needed to use cmp.Equal on Subnet as its fields are unexported. @@ -928,6 +954,10 @@ type DefaultTTLOption uint8 // classic BPF filter on a given endpoint. type SocketDetachFilterOption int +// OriginalDestinationOption is used to get the original destination address +// and port of a redirected packet. +type OriginalDestinationOption FullAddress + // IPPacketInfo is the message structure for IP_PKTINFO. // // +stateify savable diff --git a/pkg/tcpip/transport/packet/endpoint.go b/pkg/tcpip/transport/packet/endpoint.go index 0e46e6355..df478115d 100644 --- a/pkg/tcpip/transport/packet/endpoint.go +++ b/pkg/tcpip/transport/packet/endpoint.go @@ -193,7 +193,7 @@ func (ep *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMes } func (ep *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { - // TODO(b/129292371): Implement. + // TODO(gvisor.dev/issue/173): Implement. return 0, nil, tcpip.ErrInvalidOptionValue } @@ -432,7 +432,7 @@ func (ep *endpoint) HandlePacket(nicID tcpip.NICID, localAddr tcpip.LinkAddress, // Push new packet into receive list and increment the buffer size. var packet packet - // TODO(b/129292371): Return network protocol. + // TODO(gvisor.dev/issue/173): Return network protocol. if len(pkt.LinkHeader) > 0 { // Get info directly from the ethernet header. hdr := header.Ethernet(pkt.LinkHeader) diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index 1798510bc..6e5e55b6f 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -1024,14 +1024,19 @@ func (e *endpoint) transitionToStateEstablishedLocked(h *handshake) { // delivered to this endpoint from the demuxer when the endpoint // is transitioned to StateClose. func (e *endpoint) transitionToStateCloseLocked() { - if e.EndpointState() == StateClose { + s := e.EndpointState() + if s == StateClose { return } + + if s.connected() { + e.stack.Stats().TCP.CurrentConnected.Decrement() + e.stack.Stats().TCP.EstablishedClosed.Increment() + } + // Mark the endpoint as fully closed for reads/writes. e.cleanupLocked() e.setEndpointState(StateClose) - e.stack.Stats().TCP.CurrentConnected.Decrement() - e.stack.Stats().TCP.EstablishedClosed.Increment() } // tryDeliverSegmentFromClosedEndpoint attempts to deliver the parsed diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 0f7487963..682687ebe 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -2017,6 +2017,17 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error { *o = tcpip.TCPDeferAcceptOption(e.deferAccept) e.UnlockUser() + case *tcpip.OriginalDestinationOption: + ipt := e.stack.IPTables() + addr, port, err := ipt.OriginalDst(e.ID) + if err != nil { + return err + } + *o = tcpip.OriginalDestinationOption{ + Addr: addr, + Port: port, + } + default: return tcpip.ErrUnknownProtocolOption } diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go index 5d6174a59..b34e47bbd 100644 --- a/pkg/tcpip/transport/tcp/protocol.go +++ b/pkg/tcpip/transport/tcp/protocol.go @@ -49,7 +49,7 @@ const ( // DefaultReceiveBufferSize is the default size of the receive buffer // for an endpoint. - DefaultReceiveBufferSize = 32 << 10 // 32KB + DefaultReceiveBufferSize = 1 << 20 // 1MB // MaxBufferSize is the largest size a receive/send buffer can grow to. MaxBufferSize = 4 << 20 // 4MB diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index 6e692da07..b7d735889 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -483,10 +483,6 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c nicID = e.BindNICID } - if to.Addr == header.IPv4Broadcast && !e.broadcast { - return 0, nil, tcpip.ErrBroadcastDisabled - } - dst, netProto, err := e.checkV4MappedLocked(*to) if err != nil { return 0, nil, err @@ -503,6 +499,10 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c resolve = route.Resolve } + if !e.broadcast && route.IsBroadcast() { + return 0, nil, tcpip.ErrBroadcastDisabled + } + if route.IsResolutionRequired() { if ch, err := resolve(nil); err != nil { if err == tcpip.ErrWouldBlock { |